PUTNAM ON PULVINARIA INNUMERABILIS. 323 



The generative organ.^ (figs. I and 47) consist of the ovaries, ofiducts, 

 vagina, spermatlieca, vulva, and some accessory glands. 



The ovaries consist of two large organs, one on each side of the diges- 

 tive tract and filling the whole of the body cavity not otherwise oc- 

 cupied. I have not been very successful in observing the general struc- 

 ture of the ovaries, as in all ray dissections the inclosing membranes 

 have invariably been riiptured. Whatever the anterior structure of each 

 maybe, its posterior portion forms a receptacle inwliich the eggs are 

 received from the ovarioles, and then becomes contracted into a rather 

 long, slender oviduct. The two oviducts (fig. 1, hji\- fig. 47, e,eO discharge 

 into a larse vugina a little below its center (1, fc,- 47 near c). Beginning 

 at the vulva (1, m; 47,(i) the vagina becomes slightly narrowed at tlie 

 point where it received the outlets of the vaginal glands, {l.j ; 47, /t) and 

 then becomes considerably enlarged both behind and in front of the out- 

 lets of the oviducts, forming large cavities (l,f; i~.k,l], which sometimes 

 appear empty and at others to contain some not very well defined sub- 

 stance Further on it becomes contracted into a very narrow neck (1, 

 ed; 47,6) and then enlarged into a large oval sack— the spermntkeca (l.«,- 

 47,^/) which appears to have no other outlet or inlet besides the narrow 

 neck of the vagina. After copulation the spermatheca is always 

 seen to be filled with the long filamentary spermatozoa. The 

 penis of the male during the process of copulation reaches very nearly if 

 not quite to the outlets of the oviducts, as may be seen by comparing 

 the distance ok in fig. 1 with the length of de in fig. 45. One or other of 

 the cavities above and below the outlets of the oviducts may serve as a 

 burm copulatrix, or it is possible that they may serve to i-etain the egg 

 while it becomes fertilized in its outward passage, if this lias not already 

 taken place in the ovaries. The walls of the vagina and spermatheca 

 appear to be continuous, the latter thinner than the former, and to pos- 

 sess a very distinct cellular structure. On eacli side of the vagina are 

 the vaginal glands above described. The vulva appears to be simply an 

 inturning of the integument of the ninth abdominal segment. It is sur- 

 rounded by six stout spines, forming two flattened groups cemented to- 

 gether by a waxy secretion. These I have imagined to possess some of 

 the functions of an oviposter, aiding the outward passage of the eggs. 

 Extending along each side of the vagina is a large nerve sending fortli 

 several branches. There are also very numerous muscles and tracheae. 



Owing to the vast number of eggs produced by this species the partic- 

 ular structure of the ovary becomes very complex and I have been una- 

 ble to satisfactorily expli^n the relations of the different parts.* The 

 ova are developed in buds or follicles, ovicapsules of Huxley, (figs. iy-M] 

 and these are seen to be arranged in clusters (lig. 5) each cluster contain- 

 ing capsules in various stages of development. These ovicapsules appear 

 to be attached to something, a tube or membrane, through which they 

 possibly derive nourishment, while the free ends containing the large 



*lu this study I have derived much benefit from several letters written me by Dr. Mark 

 explaiuiug the prevalent views regarding the structure of the ovaries and formation of the 

 eggs, but have not always succeeded in making Ihem agree with my observations. 



