The Spermatogenesis in Pentatoma up to the Formation of the Spermatid. 31 



they vary much in size, may be distinguished from those of the earlier 

 stage by two peculiarities: 1) each mature globule is surrounded by 

 a small clear space in the cytoplasm; and 2) each stains deeply red 

 with saffranine, and red with the Ehrlich- Biondi stain or with hae- 

 matoxyline-eosin. The amount of yolk varies greatly in different cells, 

 though rarely more than two or three large globules and a few smaller 

 ones occur in the same cell. 



Of the three stages of the anaphase, the synapsis occupies the 

 longest time; and in fact more time than any other stage up to the 

 formation of the spermatid. 



b) Telophase. 



This term is used here to denote the stage between the post- 

 synapsis of the anaphase and the rest stage. The term was intro- 

 duced by Heidenhain ('94) for the final stage of mitosis in leuco- 

 cytes, in which cells he found it characterised by the movement of 

 the microcentrum to the centre of the cell. In Pentatoma no cor- 

 responding movement occurs, since here the nucleus always occupies 

 approximately the centre of the spermatocyte. But it is necessary 

 here to name the well-marked stage between the end of the anaphase 

 and the resting cell, and to this may be applied the term "telophase", 

 since it corresponds to that of the leucocytes at least in point of time. 



In the telophase (Figs. 89—93) the elongated chromosomes 

 gradually become thicker and more or less segmented, as also more 

 irregular in diameter and contour. In the telophase and synapsis there 

 is frequently a clear space in the nucleus between the chromosomes 

 and the nuclear membrane: but the telophase may always be 

 distinguished from the synapsis by three points of difference: the 

 greater size of the nucleus, the greater size and more complete elong- 

 ation of the chromosomes , and the absence of a parallel bundle of 

 achromatic fibres (mantle fibres) projecting from the idiozome to the 

 chromosomes. The changes undergone by the chromosomes in the 

 telophase are as follows. Each of the 3—6 chromosomes becomes 

 much thicker and its surface very irregular ; there also appears to be 

 a gradual decondensation of the chromatin in each, so that the latter 

 becomes finely granular or, in final stages, finely reticulate in structure. 

 The increase in diameter is also due in part to segregation of the 

 chromatin microsomes at irregular points along each chromosome, this 

 process producing a beaded or monilated appearance of the latter. 

 This segregation into clumps of chromatin along the chromosomes makes 



