THE ANATOMY. S P E R M ATO P H O R E S 137 



phore appears to be much as in Tufa/ex. But the conical head is absent aa it 

 sometimes is in Tulnfex. 



In Tubifex blanchardi, lately discovered by VE.JDOVSKY (8), the ripe spermatophores 

 have a distinct aperture at the anterior end, which, though apparently not always 

 (see figs. 7, 9 of VEJDOVSKY'S paper), communicate with the central canal. The free 

 ends of the imbedded spermatozoa form, as in Limnotlrilus, a spiral upon the outer 

 surface of the spermatophore. 



A very remarkable kind of spermatophores occur in Bothrioneuron, where they 

 have been described and figured by STOLC (3) ; as, however, his description is in 

 the Bohemian language I have only been able to use the facts so far as they have 

 been translated by VEJDOVSKY (8). These are invariably met with clustered round 

 the male-pore, where they are attached to the skin. 



The genus is exceptional among the Tubificidae in possessing no spermathecae ; 

 which organs in other Tubificids always contain the spermatophores. Their shape is 

 unlike that of the spermatophores in the other genera and is more like that of the 

 Luinbricidae. They consist of a narrow stalk and of a more swollen distal portion 

 which contains the spermatozoa. In the Tubificidae the spermatophores appear to be 

 derived from two sources ; the granular axis is the product of the secretion of the 

 ' Cement gland,' while the rest of it is produced by the epithelium of the sperma- 

 thecae. This is the conclusion of LANKESTER (2) and VEJDOVSKY a (24) ; but it must 

 be admitted that the origin is not yet definitely established. In Botkrioneuron 

 there are no spermathecae, and the structure termed by VEJDOVSKY paratrium must 

 be the place where the case is formed. The different character of the spermatophores 

 of this Tubificid correspond to the different place of their formation. 



Among the Lumbricidae spermatophores constantly occur. The most detailed 

 account of these structures is to be found in FRAISSE'S paper upon the subject. 

 They are small chitinous sacs, of an elongated, rounded form, with a more or less 

 distinct stalk. The dilated end is filled with sperm, and FRAISSE figures an aperture 

 through which the sperm can escape, when the proper time arrives. There are 

 trifling differences in form ; the spermatophores vary in shape according to the 

 species of worm. The origin that is to say the place of formation of these 

 structures has been disputed ; FRAISSE traces them to glands in the neighbourhood 

 of the setae, on the first clitellar segments, which are the tubercula pubertatis. 

 He figures, however, branching tubes in the thickness of the clitellar epithelium, 

 composed of a single layer of columnar cells surrounding a lumen. VEJDOVSKY. was 



1 The 'moulding' of the head of the spermatophoro to the shape of the distal end of the spermathecae 

 in Tulifnx ritvhrum is. of course, a strong argument. 



T 



