Why carteri?

It’s embarrassing, really. I’ve been studying Volvox and its relatives for 15 years now, and until today I couldn’t have told you who the most famous member of the group, Volvox carteri, was named for. Sure, I know Colemanosphaera is named for Annette Coleman, Volvox ferrisii for Patrick Ferris, and Volvox kirkiorum (“of the Kirks”) for David and Marilyn Kirk, but that’s because they were all named after I started studying Volvox.

But do you recall…the most famous algae of all?

I thought I’d better find out. Algaebase lists the source for the name as F. Stein 1878, and thankfully, they link to a pdf. Incidentally, Wikipedia had the date listed as 1873, which I have updated along with the reference.

Stein 1878

With apologies to my German-speaking readers, I offer the following undoubtedly awful translation (please feel free to correct!), modified from Google Translate results:

To conclude the preceding investigations on the sexual reproduction of the female Volvox the one by H. J. Carter in the year 1859 on the same object partly confirmed confirmations, partly supplementary, but they differ also in essential points and are altogether in directed against the assumption of Williamson, Busk, and Cohn, that all Volvox forms, as well as the Sphaerosira volvox belong to a single species, Volvox globator. Carter’s investigations were made in Bombay; in the local freshwater ponds seem to contain exactly same Volvox forms and Sphärosiren, as in the European waters. Carter doubted the identity of the East Indian and European Volvox forms, as the monoecious and dioecious forms also appeared among the former, and the cyst form of the female individuals in the monoecious forms was most closely related to that of the Volvox Stellatus Ehbg. agreed. The two different forms of sexual colonies made it very likely that they were the same could probably not have descended from one and the same Volvox lineage. Carter therefore turned his attention on the determination of the origin of the sexual colonies, and he not only already got to the important result that they develop in the asexual colonies like ordinary daughters and differ from these only by the far greater number of gonidia (grandchildren); he also showed that the asexual colonies that produce the monoecious colonies are different from those that produce the dioecious colonies. This was clearly proven that there were two different Volvox species. Instead of taking into account that I have already in 1854 distinguished two Volvox lineages and used the name Volvox globator in the very certain sense had, that to the Volvox Stellatus was drawn as a form of development, as Carter but had to see from the work he used Cohn’s work, he has no apparent reason and quite arbitrary called the monoecious Volvox lineage, that is to say my Volvox globatorVolvox stellatus, while the dioecious is called Volvox globator. Both names are all the more unjustified, as can be very well demonstrated that the dioecious Volvox species of Bombay certainly does not, as has often been assumed, coincide with the European dioecious species, Volvox minor, but one of them is certainly a different new kind, which I will call henceforth as Volvox Carteri. On the other hand the Volvox Stellatus Cart. exactly coincide with our Volvox globator, as I have limited it; it will therefore have to remain with my nomenclature, but now we have to distinguish three species.

This may be the earliest example I’ve come across of that most common gripe among scientists: He ignored my earlier work! Stein seems annoyed with Carter for ignoring his 1854 paper, in which Stein showed that Volvox globator is monoecious (hermaphroditic, in other words), and instead used that name for a dioecious species (one with separate male and female colonies) he (Carter) had collected in Bombay. Because the new species is dioecious, Stein is saying, Carter’s identification of the new species as Volvox globator is invalid. The new species also doesn’t match Volvox minor, so it has to be given a new name. If Stein was annoyed with Carter, it wasn’t enough to prevent him (Stein) from naming the new species after him (Carter).

The reference Stein gives is for an 1859 article by Henry John Carter in Annals & Magazine of Natural History, “On fecundation in the two Volvoces, and their specific differences.”

Henry John Carter

Henry John Carter, FRS, 1813-1895. Image by Maull & Co,, downloaded from https://pictures.royalsociety.org/image-rs-7831.

Here’s the relevant section:

Volvox globator, Ehr. PI. I. fig. 1.

Adult form.—Spherical, or nearly so, consisting of three generations or families, within one another,—that is, the parent Volvox, containing generally eight daughters, in each of which there are generally eight grand-daughters, all distinctly visible. Daughters confined to the posterior three-fourths of the sphere, the anterior fourth being empty. Progressing with the empty part forwards. Daughters rotating (this marks the adult form) in their capsules respectively, which are fixed to the internal periphery of the parent. Grand-daughters large and perceptible, motionless, and fixed to the internal periphery of the daughters respectively. Peripheral cells globular, biciliated, 57-1880ths of an inch in diameter.

Development.—The daughter consists of an enlargement of one of the peripheral cells (PI. I. fig. 11 a), which thus projects into the interior of the parent; and as it enlarges, the chlorophyll and protoplasm together are seen to form an areolar structure around the internal periphery of the cells (fig. 4), which goes on increasing in size, and the starch-cells and chlorophyll increasing in number and quantity respectively, until a sudden re-arrangement of the gonimic contents takes place, and the whole is transformed into a globe of peripheral cells. (Here is the great difference between this and the following species: contrast figs. 4 and 6 c.) Synchronously with this, the cilia are produced; the peripheral cells secrete a mucus around themselves which hardens into a thin pellicle, leaving two distinct channels for each pair of cilia; the pellicle thus hardening, the daughter separates itself from the cell-wall of the peripheral cell (the immediate parent or bud), and begins to rotate; after which, the peripheral cells of the parent waste and perish, and the capsules of the daughters, which now also contain the granddaughters or third family, becoming deciduous at the same time (for these capsules are but a part of the parent), the whole structure breaks down, and the young family, including the grand-daughters, which now become “daughters,” thus escapes. Hence the young Volvuces only contain one generation * (PI . I. fig. 3).

Fecundation.—Sometimes, instead of the eight daughters producing eight grand-daughters, and thus passing into the common form above described, two, three, and not unfrequently all of the eight daughters may present an enlargement of thirty to fifty of their peripheral cells, indiscriminately scattered over the posterior three-fourths of their spheres respectively (fig. 7). These cells, which are twice or thrice the size of the rest, and of a light yellowish-green colour while the daughters remain within the parent, become still more enlarged and of a deep dark-green colour a short time after they have been liberated; they also then become surrounded by a thickened capsule, which appears to be slightly wavy in its outline, and are, in short, the spores. Thus we see that the daughter here is the alternating form, and that she produces a cell which never becomes a granddaughter Volvox itself, but produces another cell, which in the end may give rise to a new family or third generation through the process of fecundation. Whether each spore produces one or many Volvoces, is a question which can only be decided by watching its development.

Sometimes, on the other hand, instead of either of the forms just mentioned, one, two, three, or even all the eight daughters may present an enlargement of a far greater number of the peripheral cells, viz. upwards of one hundred, indiscriminately scattered over the whole of their internal peripheries respectively. Mr. Busk states over two-thirds only (/. c. p. 33), and analogy is in his favour; but I could not detect this (fig. 8). These cells undergo deduplicative subdivision within the parent, until their contents respectively pass into 128 (?) linear, ciliated segments, which are ultimately arranged vertically upon the same plane, in a circular, tabular group, with their cilia upwards; and when the latter are sufficiently developed, the group oscillates and rotates by their aid both upon its long and short axis (fig. 10 a, b). These segments are, in fact, the spermatozoids, each of which, when they separate, is observed to be linear, horn-shaped, and colourless anteriorly, where it is attenuated, and greenish posteriorly, provided with a pair of cilia which are attached to the anterior extremity, and some distance behind them with an eye-spot (fig. 8 b); their progression is vermicular from their extreme plasticity, and they keep up an incessant flagellating movement with their cilia. As yet, I have never seen any of these free in the daughter bearing the spermatic cells when the former has been outside the parent; nor have I ever seen them free under any circumstances, except once, in the old Volvox, when the daughter containing the spermatic cells from which they had been developed had been partly eaten up by Rotatoria.

This is the form of Volvox globator which has been called Sphærosira Volvox by Ehrenberg; and, like the daughters bearing the spore-cells, it becomes liberated from the parent before the spermatic cells attain their ultimate development, that is, before the groups of spermatozoids become separated, not before they arc formed. It is worthy of remark, too, that the daughter bearing spermatic cells is never more than half the size of the spore – bearing daughter, at least as far as my observations extend.

Thus we have the spore-cells and the spermatic cells in different daughters; and as I have never seen them together in the same daughter, nor the daughters respectively bearing them in the same parent Volvox, out of some scores of instances, I can come to no other conclusion than that the two daughters meet after they have left their respective parents, when both the spores and the spermatozoids having become ripe for fecundation, individuals forming the groups of the latter separate, burst from their capsules into the cavity of the daughter, and from thence find their way out into the water, and then into the cavity of the daughter bearing the spore-cells, where they become incorporated with the latter.

Hence Volvox globator would appear to be dioecious, and not monoecious as stated by Cohn; and Sphærosira Volvox not, strictly speaking, another form of Volvox globator, but the spermatic form. Cohn, considering Volvox globator and Volvox stellatus the same species, has taken his fecundating character from the spermatic form of the latter, as will presently be seen.

It is strange that, while I have often met with free spermatozoids in the cavity of the spore-bearing daughter of Volvox stellatus, I have never been able to find any in that of Volvox globator. I have, however, frequently seen colourless, fusiform, biciliated cells in the latter, each containing a large oil-globule, which appeared to me to be the remains of the unemployed spermatozoids, as they have only been present when the spores had obtained their wavy, characteristic capsule and had become of a deep-green colour (fig. 7 a). Again, the frequent presence of Spirilla in the daughters of Volvox globator bearing impregnated spores, and their absence in those of Volvox stellatus, indicate the existence of some aperture or apertures cither prepared for, or produced by, the entrance of the spermatozoids. That such may exist without destroying the Volvox directly, is shown by the fact that Rotatoria make their way into the latter without causing them to perish.


Carter 1859 Fig. 1

Figure 1 from Carter 1859, the first drawing of Volvox carteri. Adult form, containing daughters and granddaughters; 57-1880ths of an inch in diameter: a, peripheral cell more magnified.

So Carter collected some colonies he thought were Volvox globator in India, found that they were dioecious, and said, aha, Volvox globator is dioecious! Twenty years later, Stein says, no, if you’d read my 1854 paper, you’d know that Volvox globator is monoecious. This must be a new species; I think I’ll name it after you! Incidentally, Carter’s original description was published the same year he was made a fellow of the Royal Society and the same year Charles Darwin published The Origin of Species.

Carter 1859 Figures 1-12.

Figures 1-12 from Carter 1859.

Fig. 1. Volvox globator, adult form, containing daughters and granddaughters; 57-1880ths of an inch in diameter: a, peripheral cell more magnified.

Fbj. 2. Volvox stellatus, adult form, containing daughters and granddaughters; 59-1880ths long, and 54-1880ths of an inch broad: a, peripheral cell (I am not sure, here, whether the external as well as the internal cell is not conical; it is so in the young daughter- Volvox, fig. 6 c).

Fig. 3. Volvox globator, daughter of, some little time after expulsion, and before the great-grand-daughters or fourth family have appeared. To contrast with fig. 5 at same period.

Fig. 4. Ditto, daughter of fig. 3, greatly magnified, to show the reticulated form of the gonimic contents; 18-5400ths of an inch in diameter; shows also the starch-cells, vibrating brownish granules in the reticular cavities, and marbled appearance of the chlorophyll and protoplasm. To contrast with fig. 6 c, of the same size.

Fig. 5. Volvox stellatus. daughter of, some little time after expulsion, and before the great-grand-daughters or fourth family have appeared. To contrast with fig. 3.

Fig. 6. Ditto, daughter of; more magnified view of the grand-daughter of fig. 2, 2-5400ths of an inch m diameter, to show that the gonimic contents already present the first line of segmentation, while those of the grand-daughter of V. globator (fig. 4) have reached 18-5400ths of an inch before transformation into distinct cells: a &b, magnified view of the grand-daughter on the same scale— thus showing the relative sizes of the three first stages of duplicative subdivision; c, last stage of duplicative subdivision, nearly, before the fourth family appears, 18-5400ths of an inch in diameter. To contrast with fig. 4.

Fig. 7. Volvox globator, spore-bearing daughter of, some time after expulsion; largest size seen 45-1880ths of an inch in diameter; spores 3-1880th s of an inch in diameter (the whole number of spores are not inserted here): a, more magnified view of spore after impregnation, showing the irregular form of the capsule.

Fig. 8. Ditto, spermatic-cell-bearing daughter of (Spharosira Volvox, Ehr.); largest size seen, 20-1880ths of an inch in diameter: a, spermatic cells, 3-1880ths of an inch in diameter: the whole are not inserted here. Besides the spermatic and peripheral cells, there are always several others of intermediate size, b, form of spermatozoid, 2 to 2’5-5400ths of an inch long.

Fig. 9. Volvox stellatus, daughter of, bearing spores and spermatic cells together; largest size 50-1880ths of an inch long, and 44-1880ths broad; spores 2 to 2•5-1880ths of an inch in diameter: b, b, b, b, spermatic cells, each 3-1880ths of an inch in diameter (neither all the spores nor all the spermatic cells are inserted); c, more magnified view of spore, after impregnation, showing the stellose capsule,—thus still pointing out the tendency to the conical or elongated form which exists in this species, in contradistinction to that of the other, which is globular or spherical; d, form of spermatozoid, 2-3-5400ths of an inch long.

Fig. 10. Spermatic cell after the development of the spermatozoids, but before their separation, 3-1880ths of an inch in diameter; this is the same in both species: a shows a lateral view of the group, with the dark point representing the remains of the eye-spot of the parent; b, vertical view of same.

Fig. 11. Portion of peripheral cells from V. stellatus, showing that the daughter-cell, a, is an enlargement of one of them.

Fig. 12. Spongilla plumosa, monociliated spiniferous cell of, bearing portions of indigo; 1 -6750th of an inch in diameter.


Stable links:

H. J. Carter. 1859. On fecundation in the two Volvoces, and their specific differences. Ann. Mag. Nat. Hist., III:1–20. https://books.google.com/books?id=SoM5AAAAcAAJ

F. R. Stein. 1878. Der Organismus der Infusionsthiere nach eigenen forschungen in systematischere Reihenfolge bearbeitet. III. Abtheilung. Die Naturgeschichte der Flagellaten oder Geisselinfusorien. I. Hälfte, Den noch nicht abgeschlossenen allgemeinen Theil nebst erklärung. Leipzig: Verlag von Wilhelm Engelmann. http://img.algaebase.org/pdf/1FBB00A00c42a34B15ukCF88E40A/21710.pdf

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