STRUCTURE AND DEVELOPMENT OF THE EGG-MASSES. 673 



the network are enlarged into roundish pouches. With increasing 

 size, these become more and more sharply marked off from each other, 

 and are distributed over the whole joint in place of the testes, which 

 have in the meantime gradually atrophied. When the embryos are 

 mature, the contents of these pouches are always enclosed in a com- 

 mon cementing substance, which is perhaps formed from the original 

 contents of the uterine branches, and, on becoming firm, assumes a 

 reddish-brown colour. The number of eggs adhering together is de- 

 termined by the size of the pouches. I found some clusters with only 

 eight or ten eggs (0'07 mm.), and others with seventy, or even more 

 (0'25 mm.). The flat form of the masses is explained by the fact that 

 the pouches are very closely packed, so that by mutual pressure they 

 become flattened out, usually in the direction of the transverse 

 diameter of the joint. 



During the maturing of these egg-masses, not only the repro- 

 ductive organs but the layers of substance lying between the pouches 

 gradually disappear, as indeed Mehlis has remarked. In consequence 

 of this the pouches coalesce, at first in the centre, so that the joint 

 gradually becomes an almost saccular receptacle, in the interior of 

 which the eggs remain until a rupture takes place and they are 

 set free. 



The calcareous corpuscles of Tcenia cucumerina are somewhat 

 numerous, although not so abundant as in the cystic tape-worms. 



2U 



