210 Papers from the Marine Biological Laboratory at Tortugas. 



found in the tubules nor was either kind of spermatozoa found in the 

 upper portion of the oviduct. 



The changes that the apyrene spermatozoa had undergone were quite 

 remarkable. In some cases the spaces between the albuminous bodies 

 were packed with very small darkly staining granules; in others these 

 granules had replaced the albuminous bodies in a portion of the spermato- 

 zoon; and in others the albuminous bodies had entirely disappeared and 

 the whole body of the spermatozoon was filled with the small granules. 

 In a few instances the body of the cell presented the appearance of an empty, 

 shrunken shell lying between the two undulating membranes. Clearly the 

 process going on in the apyrene spermatozoa was concerned with the 

 breaking down and ultimate exhaustion of the substance stored in the cell. 



It is probable, then, that in the examination of those dozen females 

 only the tubules of the seminal receptacle had been tapped, and not the 

 uterus, a contingency that is highly possible, depending upon the point 

 of the incision and its depth. If that were so, then the granules observed 

 were from the secretory granules of the tubules. But it is also possible 

 that the uterus itself had been tapped and that the apyrene spermatozoa 

 had undergone katabolic changes to such an extent that they were no longer 

 recognizable.^ 



OBSERVATIONS UPON THE LIVING CELLS OF THE TESTIS. 



By treating the contents of the testis in the manner already described, 

 one can make a very comprehensive, if not detailed, study of the develop- 

 ment of the apyrene spermatozoa of Stromhus. This is particularly true 

 of the later stages, where such structures occur as are represented by fig- 

 ures I to 5. These five figures, together with figure 6, show four very char- 

 acteristic stages of the developing spermatosome from the time the axial 

 fibers have grown across the cell up to and including the adult spermatozoon. 

 They give a general idea of the appearance of the living cells and of the 

 extent to which details of structure can be made out in them with the aid 

 of an oil-immersion lens (Zeis 2 mm. apochromatic) ; furthermore, they 

 bring out contours and the size relations existing between various stages to 

 the greatest possible advantage. 



In studying the living cells it was the hope of the writer not only to 

 verify the stages which had been traced in fixed and sectioned material, 



1 While a guest at the Laboratory of Marine Biology of the Carnegie Institution at Dry Tortugas during 

 June 1913, the writer had the opportunity of examining some 25 females of Strombus ^igas, all of which had 

 copulated. While it is too late to present a detailed account of this examination, it may be stated that the 

 results obtained give ample confirmation of the statements made above. The fates of the eupyrene and of the 

 apyrene spermatozoa after copulation are very different. The eupyrene spermatozoa reach the seminal re- 

 ceptacle and are stored there in great numbers, remaining alive for an unknown period. Some of the apyrene 

 spermatozoa move into the uterus along with the eupyrene, but there a sharp separation of the two kinds takes 

 place, the eupyrene spermatozoa moving into the seminal receptacle while the apyrene clump together and 

 undergo degenerative changes. Eventually the uterus becomes rid of them. But the greatest portion of the 

 apyrene spermatozoa never even reach the uterus; instead, together with some eupyrene spermatozoa, they 

 move into the bursa seminalis and there undergo degeneration until they are completely broken down. 

 Gradually the whole mass is encapsulated in a secretion from the walls of the bursa seminalis and is finally 

 extruded. In some instances it was found that the contents of the extruded capsule had become infected 

 and that putrefaction had set in. There are some grounds for the writer's belief that some of the eupyrene 

 spermatozoa which get into the bursa seminalis find their way out again and, passing up the vagina, reach the 

 seminal receptacle. The most significant point is that oviposition had not yet begun. 



The description given above of the relations of the various parts of the female genitalia is based upon 

 dissections of Strombus gigas. 



