87(3 RECORD OF CURRENT RESEARCHES RELATING TO 



the spermatopliore takes its origin in tins segment. The third 

 portion, the sjiermatophoral sac or ductus ejnculatorms, is usually 

 short and thick-walled ; in it the formation of the spermatophorc is 

 completed. The author points out that this division into three parts 

 of the male genital duct corresponds with a similar state of things 

 described by Grobbeu in the Bccapoda. 



The ripe spermatozoa accumulate at the anterior end of the testis, 

 and are carried off along the first segment of the vas deferens, the 

 lumen of which is so small, that often only two can lie side by side. 

 Arrived at the second segment, they accumulate at its hinder end, 

 being prevented from entering the third segment by a pylorus-like 

 constriction between the second and third. The second portion of the 

 duct becomes so swollen out by the accumulation of sperm, that its 

 walls are reduced to a very thin membrane ; this accumulation pro- 

 ceeds up to the bend which marks the line of juncture of the iirst and 

 second jjortions. 



Even in the first portion of the duct there is seen to be a granular 

 secretion of its wall among the spermatozoa, as well as a delicate 

 investment, also a secretion of the wall, around them. In the second 

 segment these two secretions have become much more important, and 

 there can be distinguished, from without inwards, (1) the tliin 

 investment; (2) the layers of spermatozoa; and (3) the central mass 

 of granular cement-substance. 



The rudiment of the spermatophorc thus constituted is partly 

 pushed through the valve into the third segment of the duct, and 

 the greater part of it is constricted oif to form the spermatophore, 

 part, however, remaining in the second segment, ready to begin the 

 formation of a new spermatophore. 



The author does not believe in the existence of the special secretion 

 (Sprengstoff or Austreibstoff) described by some observers, having for 

 its function the emptying of the spermatophores. 



The first section of the paper concludes with a description of the 

 male organs in the Cydopidce, the Rarpactidce, the Peltidioe, the 

 Corycceidce, the Calamidce, and the Pontellidce. 



2. The rcceptaculum seminis and the formation of the egg-sacs. — 

 This section treats of the female organs in the Calamidce., the Cyclo- 

 pida?, and the Earpadidce. The author sums up his results as 

 follows : — " Amongst the Copcpoda some sjjecies are found devoid of 

 a special rcceptaculum, others with a pair of symmetrically disposed 

 receptacula, and others again in which the organ is unpaired, and lies 

 in the middle line of the abdomen. In the first case, the semen, 

 surrounded by the cement-substance of the spermatophore, is simply 

 inserted into the vulva, in both the other cases the seminal ca2)sules 

 empty themselves, usually through a special pore, into the recep- 

 tacula, from which the semen makes its way, during the extrusion of 

 the eggs, into the vulva. The recejitacula are never also cement- 

 glands, but the secretion which forms the egg-sacs is a product of 

 the oviduct, the terminal portion of which it fills as a clear, delicate 

 mass, which sets in water. 



