206 BOTANICAL GAZETTE [MARCH 
Fic. 28. Longitudinal section of a periblem cell showing early stage in the 
formation of the achromatic figure; killed in picro-sublimate ; stained with 
Heidenhain’s haematoxylin in combination with eosin. x 2440 
Fic. 29, Longitudinal section of a periblem cell showing the formation of 
a bipolar spindle ; killed in chrom-acetic ; stained with safranin and gentian 
violet. 1750 
Fic. 30. Longitudinal section of a dermatogen cell showing the last ves- 
tiges of a nuclear membrane and the union of the fibrillations from the cyto- 
plasm with the nuclear reticulum to form the achromatic figure ; a nucleolus 
somewhat reduced in size can be seen in the spireme ; killed in chrom-acetic ; 
stained in safranin, gentian violet, and orange G. 
Fig. 31. Longitudinal section of a dermatogen cell ina = ine stage show- 
ing the chromosomes beginning to form into equatorial plate ; killed in chrom- 
acetic; stained with Heidenhain’s haematoxylin and iron alum in combina- 
tion withorangeG, x 1750. 
G. 33. Longitudinal section of a dermatogen cell showing the formalde 
of phe 2 plate and the beginning of the separation of the chromosomes ; 
absence of kinoplasm is to be noted in this preparation ; killed in Flemming’s 
weaker solution ; stained with Heidenhain’s haematoxylin with iron alum. 
X 2440. 
Fic. 33. Longitudinal section of a periblem cell, in stage just following the 
preceding ; some of the chromosomes have been cut transversely in the act of 
separation ; killed in Flemming’s weaker solution; stained with Heidenhain’s s 
haematoxylin and iron alum in combination with eosin. X 2440. 
Fig. 34. Longitudinal sections of two periblem cells in the stages of 
spireme and diaster; the upper cell shows a centrosome-like body below and 
at the right of the nucleus; killed in chrom-acetic; stained with Heiden- 
hain’s sear sidaga with iron alum in combination with eosin. 2440. 
35. Two cells from the same slide as the preceding showing similar 
bodies in the cytoplasm. 
1G. 36. Longitudinal section of dermatogen cell showing late persist- 
ence of the nucleolus in the achromatic figure; killed in chrom-acetic; 
stained with Heidenhain’s haematoxylin with iron alum in combination with 
orange G. X 2440. 
FiG. 37. Longitudinal section of periblem cell showing separation of 
chromosomes; killed in chrom- -acetic; stained with Heidenhain’s haema- 
toxylin with iron alum. 440, 
F1G. 38. Longitudinal section of periblem cell showing the passing of the 
daughter chromosomes to the poles, the vacuolar appearance and the begin- 
ning of their disintegration into tetrads; killed in Flemming’s weaker solution 
twenty-four hours!; stained with Heidenhain’s haematoxylin with iron alum. 
X< 4240. : 
F1G. 39. Periblem cell cut obliquely, giving both cross and longitudinal 
sections of the diaster; the apparent second longitudinal splitting is to be 
