108 



LEECHES 



Glossiphoniidae and Erpobdellidae the sperms pass through the 

 epidermis into the dermal connective tissue and from there to the 

 coelomic spaces in which the ovaries he (Fig. 58). He favoured 

 the view^ that there was no proteolytic action at the point of entry, 

 suggesting rather that the tissues were parted by the mechanical 

 pressure of the injected fluids. The presence of a base plate would 

 appear to be an obstacle to such action, and it therefore seems 

 more likely that, as other authors have suggested, the granular 

 contents of the lower end of the spermatophore have proteolytic 

 properties. Once attached to the body of another leech, the 

 spermatophore empties its contents into the tissues. The force 

 required to effect the transfer is probably obtained from the walls 

 of the spermatophore which shrink on contact with water. 



In many Piscicolidae there is a special area for the reception of 

 the spermatophore, called the copulatory area. In Piscicola for 

 instance (Fig. 59) it lies behind the genital pores. Immediately 



Copulatory 

 area 



Fig. 59. Ventral view of part of body wall of Piscicola, showing 

 genital pores and copulatory area. After Brumpt, 1900. 



beneath it there is a pad of fibrous connective tissue with two 

 strands running to the ovarian sacs. It is called conducting tissue. 

 The spermatophores are normally deposited on the copulatory 

 area and the sperms travel most readily through the underlying 

 fibrous connective tissue, and are conducted direct to the ovaries. 

 In other Piscicolidae, such as Callobdella lophti, there are 



