570 Existence of Permanent Forms among Chromosomes, etc. 



DESCRIPTION OF PLATES. 

 Plate 24. 



Fig. 1. — Groups of cells from the testis of a Triton. They are all in phases of the first 

 maiotic (heterotype) division, and similar forms of gemini (heterotype chromo- 

 somes) are to be seen in numbers of different cells, as at b, c, d, g, f. 



Fig. 2. — Cells from the testis of a Triton, all in the late prophase of the first maiotic 

 division. In three of the cells the nuclear membrane is still present ; but the 

 gemini have already assumed the same forms as those represented in fig. 1, 

 b, c, d, g, f. 



Fig. 3. — Cells from the testis of a rat, showing similar gemini in the different cells, 

 a, c, e,f, h. 



Plate 25. 



Fig. 4. — Cell from testis of a rat. Early phase of first maiotic spindle, showing pairs of 



different gemini, a, b, c, d, e. 

 Fig. 5. — Group cells from the testis of Periplaneta, showing similar gemini in each of 



the three different cells, a, b,f, g, h. 

 Fig. 6. — Cells from the testis of man, showing similar gemini in the three cells at a, c, e, h. 



