GROWTH OF EGGS AND EGG-STRINGS IN NEPHELIS. 197 



sections, a macerated portion of the epidermis. The two 

 bottle-shaped tubes were filled with spermatozoa, and 

 opened by means of two distinct holes in the disc. From 

 each of these openings a stream of spermatozoa was found, 

 penetrating to a considerable depth into the underlying 

 tissues. In section the substance of the two-horned body 

 appeared dotted, and longitudinally striated, but I was 

 unable to recognise any cellular structure. 



For a long time I Avas much puzzled as to the meaning of 

 all this, but from further observation was led to regard it as 

 a case of abnormal or unsuccessful copulation. 



When disturbed during the act of copulation, the two 

 leeches usually separate immediately ; but in one instance 

 they did not separate even after putting them into chromic 

 acid. On examination I found that the female orifice of 

 each leech was not in contact with the male orifice of the 

 other, but that each individual was attached to the ventral 

 surface of the other by its male orifice, the female orifice 

 remaining free. On sei)arating them by force, each male 

 orifice left the two-horned object on the body of the other. 



In another instance that came under my notice, only one 

 individual had already deposited the two-horned body, while 

 tlie other had a mass of spermatozoa hanging from its male 

 orifice. The latter was dissected, and the two-horned body 

 found occupying the whole interior of the ejaculatory organ, 

 with the cavity of which it exactly corresponded in shape. 

 It came out without any resistance. It thus became evi- 

 dent that the two-horned body belongs to the interior of 

 the ejaculatory organ. That it forms no permanent part 

 of the male organ, seems evident from the fact that sec- 

 tions made in the winter show no trace of such a body. 

 I have not thus far been able to determine whether this 

 body forms in the case of normal copulation also. As to its 

 mode of formation. I have nothing to offer except the con- 

 jecture that it may be the hardened secretion of some of the 

 glands of the ejaculatory organ. 



On many leeches were found scars, which very likely may 

 have been the marks left by these peculiar bodies. 



It is hardly to be doubted that the normal mode of 

 charging the ovaries with spermatophores is through the 

 female orifice. It would certainly be impossible for the 

 spermatozoa to find their way into the ovaries in many of 

 those cases which we have described as abnormal, espe- 

 cially where the injection takes place far in front of the 

 male orifice. 



Cocoons, and their contents. — If well fed with fish-meat 



