220 Dr Gairdner's Analysis of 



sumes a greenish-grey colour. These rounded bodies commu- 

 nicate by a canal, scarcely perceptible in the unimpregnated 

 state, broad and distinct when nearly ripe, with the cloacal di- 

 latation formerly noticed as existing near the anal orifice of the 

 intestine. That the ova are not internal gems^ an opinion enter- 

 tained by many older observers, such as Lamarck and others, is 

 proved not only from the above mentioned development and 

 connections of their containing vesicles, but also by the distinct 

 existence of the three substances which in the ova of the Entozoa 

 M. Rudolphi considers as the chorion, allantois and amnion. 

 In the centre of many ova there can be recognised a darker 

 point, which is cither the embryo, or cicatrix in which the latter 

 is developed. 



The adult Hydatina possesses, besides, two organs which Dr 

 Ehrenberg considers as the male organs of generation, but the 

 real nature of which is a little more doubtful than that of the 

 preceding. They resemble very much in form the milt of fish, 

 consisting of two elongated bodies, extending nearly the whofe 

 length of the animal, exterior to the ovaria, broader towards the 

 head, dimiiiishng towards the tail. They terminate (a strong 

 corroboration of this view of their true nature) in a number of spi- 

 rally convoluted tubes, which finally open by two separate canals 

 immediately behind the oviduct. These spiral convolutions are 

 enveloped by an organ of a very singular nature, the function 

 of which is very obscure : it is oval, transparent, remarkable for 

 its irritability and sudden changes of form ; at one time swell- 

 ing out into a vesicular form, at another contracting into a small 

 glandular looking organ. Dr Ehrenberg at one time considered 

 it to bear some analogy to an uterus ; but it is more probably 

 connected with some office in applying the seminal fluid to the 

 ova previous to the exclusion. This organ is wanting in the 

 Rotifer and Philodina, where the inale apparatus otherwise re- 

 sembles very closely that of the Hydatina. 



In the Kolpoda cticuUus, the parent animal excludes the ova 

 in the form of extremely minute globules, bearing much simila- 

 rity to some of the species of the genus Monas, connected by a 

 number of filaments interwoven together in a reticular form. 

 In an animal ^^^th of a hne in diameter, that of the ova was 

 ygijoth pf a line. The young Kolpoda were ^lith of a line 



