570 SUMMARY OF CURRENT RESEARCHES RELATING TO 



and there are annual prespermatogenetic outcrops before the true sper- 

 matogenesis. 3. The cells called primitive spermatogonia are sexually 

 indiiferent cells. They are often transformed into oviform cells. Their 

 degeneration most frequently recalls an abortive oviform development. 

 They are the seat of relatively active processes of elaboration, especially 

 during the interspermatogenetic period ; or rather, there is a prepara- 

 tion for an active elaboration which is not followed up. 4. The sper- 

 matogonia of the second order are very different from the primitive 

 spermatogonia. They are definitely differentiated in the direction of 

 male cells. They are pre-spermatocytes. 5. The known stages in the 

 development of the spermatocytes, as described by Jannsens, are con- 

 firmed, but the chromatin appearances suggest the desirability of caution. 

 The appearance of synapsis appeared artificial. The most important facts 

 in the development of the spermatocytes are : the repair of the chromatin 

 after the last spermatogonial telophase, the length of the first prophase, 

 the shortness of the second, and the similarity of the two maturation- 

 divisions. 



6. In the spermatids, from their formation, there is a division of the 

 cellular centre. This gives rise to two groups of centrioles. One of 

 these retains almost the whole substance of the centrosome, and forms 

 the acrosome or a part of the acrosome. The other forms, as is known, 

 the .flagellum. 7. The spermatids show an axial spirostyle or rodlet 

 within the nucleus. It begins to develop at the anterior pole of the 

 nucleus, and often seems to be in relation with the anterior group of 

 central corpuscles. It always comes secondarily into relation with the 

 acrosome, and this relation persists. This axial rodlet twists in a spiral, 

 involving in its torsion the nucleus and even the cytoplasm. The degree 

 of torsion differs in different species ; it is sometimes rudimentary ; in 

 the fully formed spermatozoon it is imperfectly or exceptionally visible. 

 The acrosome participates in the torsion of the spirostyle, of which it 

 seems to be the extra-nuclear portion. 



8. In Urodella there is an endocrinal glandular tissue in the testis. 

 It forms around the empty cysts and affords good illustration of the 

 process of endocrinal secretion. It has only a transitory existence and 

 recalls the corpus luteum of the Mammalian ovary. 9. In Anura the 

 interstitial testicular tissue differs in different species. It always retro- 

 gresses at the time of the chief spermatogenetic activity. 



Champy emphasizes a number of histological conclusions to which he 

 has been led. The mitochondria play a part in the production of inclu- 

 sions. The chondrikont is the relatively resting aspect of the chondriome. 

 The occurrence of the isolated grains indicates an active transformation 

 into deutoplasm. The transformation of the mitochondria into deuto- 

 plasm, notably into fat, is preceded by the formation of special plastids or 

 chondrioplasts. 



The centrosome may divide apart from the prophase of the mitosis. 

 This is not unfrequent in cells with an active deutoplasmic elaboration, 

 as in the oviform cells and the interstitial glandular cells. In these 

 elements the centrosome often occupies an excentric position, towards 

 the area in the cytoplasm where the elaboration is most active. 



The pyrenoid bodies (or chromatoids of Hermann) have a nuclear 



