I ORGANIZING ASPECTS OF GAMETOGENESIS 307 



our knowledge of general cytology, so considerably increased in recent years by 

 electron microscopy, we may guess that this descendance implies the transmission 

 of (a) mitochondria, with some kind of internal partitioning and a complex 

 enzymatic equipment, (b) the cytoplasmic reticulum, mostly phospholipidic (ana- 

 logous to the ergastoplasm of secretory cells), and the attached Palade's granules 

 which bear most of the RNA, both these structures corresponding to the fraction 

 obtained by centrifugation which has been called microsomes, (c) the host of Golgi 

 vesicles mostly grouped around or near the nucleus, (d) the centriole(s) whose 

 significant complexity has been described in several mouse and chicken adult 

 cells (De Harven and Bernhardt, 1956). Moreover, less individualized macro- 

 molecules of the cytoplasm, especially proteins, including enzymes, may be in 

 material continuity with the same components of the parent cells, as are also 

 possibly the mucopolysaccharides and other specialized compounds. Of these 

 numerous plasmatic constituents, the centrioles do in fact reproduce themselves 

 by division, but for all others, such division has not, in the best cases, been 

 proved with certainty. Some or most of these organelles or even the macro- 

 molecules may either reduplicate, be replaced thanks to some recombination 

 or growth, or be synthesized from more minute elements. How much these 

 events, whatever they may be, depend upon the nucleus, or, more specifically, 

 upon its genes, remains an open problem. As a result of several observations 

 {cf. pp. 332, 480) we have some reason to conclude that they are dependent on 

 nuclear activities, especially on the nucleoli, which implies definite activities of 

 the chromosomes. However, to assert that all cytoplasmic features depend on 

 genes would be based only on the conviction that the manifestation of certain 

 hereditary characters proves that genes influence mitochondria, or ergasto- 

 plasmic structures, or the Golgi system. This would be merely a postulate. 

 Therefore, we should leave the problem of the relations between genes and the 

 cytoplasmic organelles, a task for further exploration. 



Consequently, we cannot simply assert that the hereditary endowment of 

 spermato- or 00-gonia is located in the genes. They are indeed the carriers of 

 many characters, but neither the rest of the nucleus nor the fundamental con- 

 stituents of the cytoplasm, with their species-inherent properties, can be ignored 

 without risk of an error. The whole system must be taken into account when we 

 try to describe the morphogenetic organization of the egg. 



B. Growth and polarization of the oocytes 



We shall pass rapidly over the period of multiplication without discussing the 

 problem of the stem cells, which has been solved recently in some spermato- 

 geneses (Cleland, 1951; Leblond and Clermont, 1952; Roosen-Runge and 

 Barlow, 1953), but consider the period of growth in the young auxocytes. Here 

 we must mention the evident link between the male or female gene complex and 

 the respectively limited (d ) or complete (9) growth of the auxocytes. 



In all groups, excepted sponges and nematods, the male gamete, when having 

 performed its meiosis and attained the stage of spermatid, elongates and builds 

 up an elaborate system of fibrillar and granular differentiations, which insures 



Literature p. 483 



