93 



of Lumhricus ; like them these glands occur in the genital segments ; 

 the absence of any histological description of the capsulogenous glands 

 in Lumhricus prevents me from identifying the two series of glands 

 with any certainty. These glands have already been noticed by Per- 

 ii er in P. aspergillum and P. affims\ in the former species they are 

 a series of minute white glands opening by a number of orifices round 

 the apertures of the vasa deferentia and those of the spermathecae; in 

 the latter they open on to the genital papillae of the 17'^ and 19'^ 

 segments. 



In P. mirabilis the orifices of these glands are very conspicuous 

 and are five in number; three on one segment, one median and two 

 lateral ; a single median pore on the following segment. I am not certain 

 whether the species referred to here is really Bourne' s P. mirabilis but 

 in any case it comes near to it. In P. aspergillum I find exactly the 

 same disposition of the orifices of the glands round the male pores that 

 Perrier has described, but not round the pores of the spermathecae. 

 There are a pair of orifices on each of segments, they lie a little to the 

 outside of the spermathecal pores, for which they might well be mis- 

 taken, as the latter are often invisible. This difference may however 

 be of specific value. In both species the glands have the same struc- 

 ture; they consist of groups of unicellular glands; the cells 

 are leaded with granules and each communicates with the exterior by 

 means of its own duct which is simply a prolongation of the cell ; in 

 the case of P. aspergillum each group of gland cells is separate and 

 opens on to the exterior by a separate pore ; in P. mirabilis the groups 

 of gland cells are partially fused Avith neighbouring ones; the duct of 

 each group, which as in P. aspergillum consists of the prolongations of 

 the several cells bound up in a common sheath, traverses the integu- 

 ment independently, but the external apertures are common to a con- 

 siderable number of ducts. 



In P. Houlleti Perrier has stated that the spermathecae (of which 

 there are 3 pairs) are each furnished with two diverticula; one is a 

 tube bent upon itself several times , the other a pearshaped body. I 

 find this to be the case in some specimens ; in others there were often 

 two pearshaped bodies attached to a single spermatheca. The structure 

 of these is not the same as that of the coiled diverticulum ; the latter 

 has a lumen which is lined with a cubical epithelium; the pearshaped 

 diverticula consist of a solid mass of granular cells and in fact agree 

 in every particular of structure with the »capsulogenous« glands of 

 P. mirabilis and P. aspergillum. They only differ in that their ducts 

 open into the terminal region of the spermatheca. The differences 

 in the number and position of the «capsulogenous« glands 



