33 221 



The young female when first hatclied is of much the same size luid .iiipearance as the 

 male; but the large, white, rounded, salivary glands attached by a narrow neck to tlie mastax, 

 and the large and full gastric glands, as well as the ovary and stomach, which together till 

 up the whole body cavity, serve to distinguish it at once. Both the young mak' an<l rcmale 

 escape from the galls in which they have been hatched by an opening wliich is formed at 

 the apex. They swim about in the open water for a time, whereupon the young female again 

 enters a Vaucheria lilament, but where and by what means is not exactly known. It causes 

 the plant to produce a rounded or elongated gall of considerable size; it seems that the female 

 is unable to develop and lay eggs outside the Vaucheria filament or gall. The adult I'emale is 

 almost globular with a lai-ge number of immature eggs. Most probably intestine and stomach 

 are active. Some galls contain all female eggs, others both female eggs and the smaller and 

 fewer male eggs. Fertilised resting eggs were found by Rothert in a nundjer of 3U— 54 in one 

 gall, all laid by a single female. 



Proales parasita Ehrbg. 

 Tab. 1, fig. 4—6. Tab. IX, fig. 7—12. 



Description: Body cylindric, very short. Wheel-organ placed almost vertically, 

 consisting of a row of cilia; upon the disc a horse-shoe shaped second row with 

 somewhat longer cilia. (Tab. I, Fig. 6). Brain very large; dorsal antenna most prob- 

 ably present, but has not been observed; lateral antennæ not observed; a very large 

 red eye placed behind the brain; no trace of alimentary canal. Testis very large, 

 pearshaped, opening dorsally; no penis but the ductus seminalis can be turned in- 

 side out; at the opening a tuft of cilia. Two prostata glands. No trace of excretory 

 organs. A real foot does not exist, but there is a peculiar sharply defined small ap- 

 pendix, ending in two spinelike projections. There are six or seven transversal 

 muscle bands and two pairs of longitudinal ones. The interior is filled with a greyish 

 mass, containing very many oil globules. Size of male 40 //, of female 160 //. 



It is only with some doubt that I refer this species to Proales parasita. This as 

 far as I know has hitherto only been found in Volvox, in which I have often found 

 the animals too. Mj^ specimens all derive from Uroglena vohwx. Owing to the smaller 

 size of this alga the animals do not alwaj's live in the colonies ; very often they sit on 

 the outside, feeding upon the surface. Often the}' jump off, swimming round the co- 

 lonies. The eggs are laid upon them. When newly hatched, the females are small, 

 narrow and rather quick in their movements; but in the course of a few days, after 

 having fed upon the Uroglenas they begin to swell; the foot with the toes is almost 

 always held withdrawn, and at last the whole body is quite deformed. (Tab. I, fig. 

 7 — 12). In this shape the animals hardly ever leave the colonies, often living within 

 them and almost filling them up. When Uroglena colonies are not at hand, the ani- 

 mals live their life as freesw^imming organisms, and the females keep the shape in- 

 dicated in fig. 8. The females possess no tentacle in the wheel-organ and cannot there- 

 fore be identified with Hertwigia volvocicola Plate. As I cannot find any difierence 

 between the Proales parasita Ehrbg. and my specimens, deriving from the Uroglena 

 colonies, I refer them to this species. In my area of exploration it is common in May. 



D. K. D. Vidensk. Selsli. Slir., naturv. og malhcm. Afd., 8. Hække. IV, 3. 3(j 



