326 AUSTRALIAN HIRUDINEA, I., 



than the former. In the region of the clitellar swelling, which 

 lies in front of the genital apertures, the glands are absent, and 

 we find the same condition for some distance on either side of this 

 swelling. 



The dermis is of considerable thickness, and consists of a matrix 

 in which occur numerous cells with a large nucleus, and also 

 diagonal muscle fibres. These fibres are, according to Bourne, 

 absent in the species which he examined. The cells mentioned 

 above as occurring in the matrix constitute the " excretophores " 

 of other species of Glossiphonia. 



The circular muscle fibres form a layer equal in thickness to 

 the combined epidermis and dermis. 



The longitudinal muscle fibres are arranged in masses beneath 

 the circular fibres, the groups being separated from each other 

 by dorsi-ventrally directed fibres. These longitudinal fibres 

 show very distinctly, in their cortical position, the striations 

 seen in the other members of the Hirudinea. 



The body-substance consists of a vacuolated mass, scattered in 

 which are the complex series of sinuses, various kinds of corpus- 

 cular cells, and the salivary glands. 



The salivary glands far exceed in size any other cellular 

 elements in the body, with the exception of the ova. In sections 

 they appear as chains of large oval or spherical cells deeply 

 stained. They extend in each side of the body from the anterior 

 limits of the ventral nerve cord to the posterior extremity of 

 the ovaries, and thus form very conspicuous elements. 



Fat cells are abundantly distributed through the body, inas- 

 much as abundant cellular elements occur containing a nucleus 

 and very scant cytoplasm. 



Graf has attributed to the " excretophores " an excretory 

 function, thinking that they take up excretory products in the 

 deeper portions of the body and then travel towards the surface 

 of the body and disintegrate. With this belief I am in accord. 

 The great abundance of these cells and the great diminution in 

 the development of the nephridia in Glossiphonia australiensis 

 incline me to think that the "excretophores" have the function 



