296 108 



frei in der Nähe der Kolonien und zwar 3 — 7 bei einer Kolonie: nur bisweilen befestigen 

 sie sich. Size Male: 300— 7I1Û //. Female 1500—2000. 



Hamburger (1907, p. 625, Tab. XXXI) has given a very thorough description 



of the male. The following is a condensed abstract of her text. 



The body of the male is somewhat conical; the coronal disc somewhat vaulted; en- 

 circled b\' a closed ciliary wreath and carrying on its top a bunch of cilia and other cilia 

 spread over the disc. The hypodermal cells large and regularly arranged. Brain rectangular, 

 giving off nerves for the two red eyes and for the two lateral organs lying between the second 

 and third transversal muscle, and for the dorsal organ, which has not been observed with 

 certainty. It is of interest that H.\mburger has pointed out an oesophogeal commissure only 

 rarely observed in the Rotifera: Discopus Zelinka (1888, p. 235) and Conoc/jz'/o/des (Hlava 1905, 

 p. 282). Xo alimentary canal, but rudiments between testis and the hypodermal cells of the 

 wheel-organ; even a rudimentary mastax is supposed. Two lateral canals which are supposed 

 to be in connection with each other by means of a transversal commissure' beneath the brain ; 

 they debouch in the proximal part of vas deferens. The number of vibratile tags is not indi- 

 cated, but "Treibwimpern"" in the lateral canals are obsers'ed. The testis is very large and 

 contains two sorts of spermatozoa; the vas deferens (^= ductus seminalis) is built of a layer 

 of ring muscles and covered inside with a coating of long cilia. Two prostata glands; to the 

 posterior part of vas deferens two muscles are attached, which, according to H.\mburger, 

 come into action when the spermatozoa are to be forced out. After a restriction the vas 

 deferens is again expanded and coated with long cilia; there is no penis, but H.4.mburger 

 correctly supposes that it is this part of vas deferens which, when turned inside out, acts 

 as a penis. The opening of vas deferens is situated dorsallj*. Over the testis an opaque mass, 

 which Hamburger in accordance with Pl.^te regards as a remnant of a rectum. Below the 

 genital aperture on the very apex of the body a cilia-coated sucker is found, into the bottom 

 of which two glands open. These glands may be homologous with the foot glands of the 

 female; the vasa deferentia for these glands are swollen and used as reser\-oirs for the secre- 

 tions of the glands. Seven or eight transversal musclebands are indicated, further the great 

 retractors of the wheel-organ. Length of animal 200 — 300 //. H.«iburger has given a valuable 

 contribution to the Spermatogenese and pointed out the great difference between the two sorts 

 of spermatozoa. Pl.\te and H.^mburger suppose that the males fasten themselves by means of 

 their sucker upon any part of the body and that the stafformed spermatozoa are used as 

 weapons b\- means of which the bod>-Avall is pierced. The mating process has not been observed. 



The species was found in Gudenaa twenty years ago. It occurred here in countless 

 numbers, and in July the males swarmed round the colonies. As the animal was 

 observed on a journey, it was only badly drawn; later on it was found on the under- 

 side of the leaves of Xymphæa in a pond near Hillerod (Carlso); in 1920 when the 

 colonies should have been collected a boat could not be obtained. Finally in 1921 

 it was found in Susaa near my summer laboratory, and I had good opportunity to 

 study the male. Comparing my description with that of Hamburger I could find no 

 differences and I therefore refer the reader to hers. 



Geeistes mucicola Kell. 

 Male. Western 1891, p. 321. 

 Western (1891, p. 321, PI. XXI 1 c) writes: 

 "I also found what appears to be the male, though I did not actually see it hatched 



