238 



Mr. R. J. Ludford and Dr. J. B. Gatenby. 



and early telo-phases, the dictyosomes are scattered irregularly in the 

 cytoplasm, and during the late telophase, when the chromosomes are com- 

 pletely separated ofif into the two daughter cells, the dictyosomes come 

 together again and become attached once more to the archoplasm. Early 

 and late telophases are shown in figs. 5 and 6, and the reconstructed compact 

 form of the apparatus is shown in the case of the recently formed sperjnatid 

 in fig. 8. 



Both in the primary and secondary spermatocyte divisions, the process 

 of dictyokinesis is essentially the same. About the time that the nuclear 

 membrane breaks down, the archoplasm, with the dictyosomes, divides. 

 During the metaphase the dictyosomes become scattered, and towards the 

 end of the telophase they are attracted once more to the archoplasm, to the 

 surface of which they become attached. 



The role of the Golgi apparatus from the spermatid stage onwards has 

 ■already been described by Gatenby and Woodger* in the case of Cavia. 

 The greater part of the mammalian Golgi apparatus has been shown to be 

 sloughed off during the formation of the spermatozoon, but a few dictyosomes 

 remain attached to the middle piece. The beginning of the sloughing off 

 process in the Mus is shown in fig. 9. 



Dictyokinesis in Cavia. 



Dictyokinesis in Cavia cohaya is, with few exceptions, essentially the 

 same as in the case in Mus. The process in this mammal has been studied 

 in preparations made by Weigl's modification of the osmium tetroxide 

 method of Kopsch. 



During the early phases in the development of the spermatocyte, the 

 archoplasm to which the dictyosomes are attached shows a remarkable 

 frothing. This is shown at "b" in fig. 16, and again at VV in fig. 12. 

 Small " bubbles " appear to arise peripherally upon the archoplasm ; they 

 increase in size and, owing to the fact that later they disappear, it would 

 seem that they burst and discharge their contents into the cytoplasm. 

 Peripherally, these bubbles are surrounded by a substance which stains 

 black with osmium tetroxide. At the end of the diakinetic stage of the 

 chromosomes the formation of these " bubbles " upon the archoplasm ceases, 

 and the dictyosomes are then seen as semilunar rods attached peripherally 

 to the archoplasm, as is shown in fig. 16 at " a." 



Before the nuclear membrane disappears the archoplasmic mass, which 

 has enlarged during the growth period, begins to divide in exactly the same 

 manner as in Mus. The beginning of division is shown in figs. 13 and 14 

 * 'Quart. Jour. Micr. Science,' 1921. 



