No. I.] SPERMATOGENESIS OF BATRACHOSEPS. 43 



or rather in its concavity. At the poles of the central spindle 

 we find always one and generally two archosomes. Sometimes 

 the two are connected by a thin thread of somosphere. Some- 

 times this thread is double, the two archosomes being situated 

 at the opposite ends of a dark-staining ring. At the end of 

 the anaphase the archosomes have gradually diminished in size 

 and staining capacity, and are then only visible by the most 

 careful optical manipulation. I have no doubt that in in- 

 stances where the archosome has not been figured in this 

 stage of mitosis, the failure to observe it is referable to insuffi- 

 cient optical means, and not to an actual absence of the archo- 

 some. In the confluent umbrella stage the archosome is, 

 however, not to be distinguished. But at this stage the apex 

 of the central spindle has also disappeared, to reappear later on 

 below the nucleus. With its reappearance an archosome with 

 a single centriole is also seen at the pole of the fibers, and we 

 may with some reason presume that it is the same one that was 

 previously situated above the nucleus, but which has followed 

 the central spindle and been pulled through the ring-like 

 nucleus (Figs. 54-61, 6^, 64, 69, 70). As the granosphere is 

 reconstituted around or near this pole, it follows that the archo- 

 some will be found in or near the new granosphere. But if 

 the same archosome will always perform the same function in 

 the new cell is doubtful ; it frequently appears as if the place 

 of the archosome in the new spermatocyte was taken by some 

 accessory archosome, already at the pole of some spindle cone. 

 The Accessory Archosofnes, their Structure and Functions. 

 Expulsion of Superfluous Archosomes. — As the accessory arch- 

 osomes have already been referred to in the preceding para- 

 graph, I will here only describe a few points not yet touched 

 upon. We have seen that the accessory archosomes are quite 

 numerous, but of varying number. In the earliest stages of 

 mitosis they are more numerous than in the later ones, and it 

 appears that they are in some manner used up. At first they 

 circle around in the spheres apparently without any regularity ; 

 later on they arrange themselves around the archosome at the 

 pole of the central spindle. My observations are not conclu- 

 sive, but they tend to show that the accessory archosomes 



