PACIFIC COAST OLIGOCH^-TA. 79 



tiiiu coiupanUivcly few blood gluiulsi, others three or four times as many. They 

 are of all sizes and shapes, as Perrier has "shown. Some contain only one single 

 nucleus, then frefpiently surrounded by a blood clot; others again contain a very great 

 number of nuclei, which are then situated in a sac-like pocket at the end of the blood 

 capillary. In some of the larger blood vessels in the salivary gland the blood gland 

 takes the form of a " hertzki)rper." The smaller ones situated on the capillaries 

 may be named terminal blood glands, while those situated inside the larger vessels 

 may be designated interior blood glands. The structure of the two are at least in this 

 species very similar. 



In fig. 73, a. to .s., I have cn<lcavored to illustrate the structure of these blood 

 glands from sections. In (j.a large blood vessel with a blood clot, at the base of which 

 is an inner blood gland. On one side of the blood vessel is a part of a salivary gland 

 with brown secretions. In a. a small terminal blood gland is shown, and in h. and e. 

 some of a greater development. The nuclei are not always surrounded by a distinct 

 cell membrane, in fact in almost every gland are found some nuclei with distinct cell 

 membranes while others lie loose in the granular serum. The exterior line in all 

 the figures represents the wall of the blood vessel, and the difference between the 

 terminal and inner blood glands consist in reality only in the absence or presence of 

 blood surrounding the glands. As far as the granular protoplasm concerns it is always 

 differentiated in two parts. The one at the distal extremity is more evenly dif- 

 fused and finer grained than the one next the capillary, which again is coarser, streaky 

 and which, besides, stains differently or at least more intensely than the other. Many 

 of the glands contain larger or smaller bodies {p., t. and o.) equally of round form 

 and lighter in color than the cytoplasm, but sometimes they are very opaque, stain- 

 ing deeply as at r., the two classes probably being of entirely different character. 

 The former resembles a pale nucleus, while the latter opaque bodies appear only to be 

 secreted matter. The paler ones may possibly be parasitic protozoa. 



The blood glands described by Claparede, Lankester and others in Lumbricus, 

 etc., are probably of a similar construction, and judging from the figure given by 

 Michaelsen of the " hertzkorper " in Enchytrseus, we may conclude that it, too, is 

 identical with the blood gland in Pontodrilus. 



Spermathecre (figs. 30, 55, 5Q, 57, 58). There are two pair of spermathecse 

 found in somites viii and ix, the exterior pores being as usual in the intersegmental 

 grooves between vii/viii and viii/ix in line with setse 2. Each spermatheca possesses 

 a tubular diverticulum, the junction of the two being in the body-wall. The position 

 of the diverticulum is always ventral to the spermatheciB proper. This is cylindrical, 

 quite narrow, with a larger globular chamber at the free inner end, in which the wall 

 is much thinner than in the cylindrical part. At the junction with the body-wall 

 is a much larger swelling, the lower and more strongly muscular part of the main 

 cylinder being greatly widened, presenting a muscular cushion partly projecting above 

 the body-wall, partly again being immerged in it. The spermatozoa are principally 

 massed in the inner globular chamber, though they are seen also in the diverticulum. 



