304 116 



As far as we hitherto know, all the males of the Flosculariidcr are freeswimming 

 animals, without gelatinous tube, cylindric or cone-shaped; no peduncle; it is doubtful 

 if there exists a sucker, by means of which the male may fasten itself to the female; 

 something in this direction may perhaps be interpreted in this way in the figure of 

 Montgomery (fig. 36 x y). In the male of Floscularia ornata, I could find nothing 

 of that. 



The coronal disc is always placed vertically, covered with a rather uniform 

 coating of short cilia and encircled by a simple wreath of cilia; no setigerous lobes 

 or long seta? have ever been observed in a male of the Flosciilariida', and as the whole 

 alimentary canal is absent, there is not the slightest trace of the highly specialized 

 vestibulum, so characteristic of the female. All species present two red ej'e spots, 

 placed on the cone-shaped disc. From brain conspicuous nerves are given off to a 

 dorsal organ, which is most probably always present; whether the same is the 

 case with the lateral antennæ is doubtful; hitherto they have only been observed 

 in Stephanoceros and in Apsilus, The alimentary canal is wholly absent, a rudiment 

 as a suspensor testis perhaps present. Excretory organs present as two lateral ca- 

 nals with a series (3 — 4) of vibratile tags; they have only been observed with cer- 

 tainty in Stephanoceros, Apsilus and Floscularia proboscidea (by Weber) and in F. 

 ornata (by myself); the contractile vesicle is supposed to be present in Stephanoceros 

 and in Apsilus. 



The testis is always large, pyriform; whether it always contains two sorts of 

 spermatozoa is rather doubtful, pointed out in Apsilus; the ductus seminalis is short, 

 now and then curved, coated with cilia inside, opening dorsally. There is no real 

 penis but most probably during the mating process the last part of the ductus se- 

 minalis is turned inside out. Prostata glands are always present. A long series of 

 transversal muscle bands and strong longitudinal muscles. 



The males are hatched in the tubes of the females and their freeswimming 

 period most probably very short. ^ 



Chapter TV. 



Anatomical Remarks Relating to the Males of the Rotifera. 



In the following Unes 1 have tried to give a sketch of the structure of the 

 males of the Rotifera. With regard to some of the organs, this is onh' possible with 

 full consideration of the same organ in the female sex. When this is the case, the 

 description has been begun with a more general survey of the organ in this sex, 

 laying weight upon just those points which are of significance for the understanding 

 of the structure of the same organ in the male sex. 



1 RoussELET (1903, p. 174) states that Thorpe has found the male of Trochosphara œquatorialis; 

 ■with regard to the very aberrant males of the Seisonacea, I refer the reader to the papers by Plate and Claus. 



