348 



Mil, a. a. BEDDABD ON JiAETRAVOSMS 



[Apr. 16, 



not completely ascertained ; in Polytoreutus there are no facts 

 which prove one or the other origin for these structures. The 

 spermatophores of StuJilmannia are very large ,; the largest which 

 I measured was fully 3 mm. in length, and it must be noted that 

 the diameter of the worm in which it occurred was only 2 mm. 

 The spermatophore, therefore, lias to lie longitudinally in the 

 spermathecal sac. 



Text-fig. 86. 



Spermatophore of Stuhlmannia, greatly magnified. 



The form of the spermatophore is illustrated in the drawing 

 (text-iig. 86). It is not by any means imlike a cestoid worm, for 

 which, indeed, for a moment I mistook it. The strongly pronounced 

 "head" and the bag-like body widening irregularly is very like 

 the immature stage of those parasitic worms. The" shape is not, 

 however, suggestive of that of any other spermatophore with 

 which I am acquainted, either at first hand or by descriptions. 

 It has the length of the longest sperm atophores of Folytoreuttis, 

 but the wideness and bulk generally of the spermatophores in the 



