SUBJECT INDEX 



Toad, egg of, ultraviolet absorption in, 1 5 

 erythrocytes of, DNA content, 34 

 spermatocytes of, 44 

 Tobacco mosaic virus, 130 

 Toluidine blue, 4, 9, 10 

 Tonicity, alteration of, 135, 145 



erythrocyte permeability, effect on, 185 

 mitosis, effect on, 185, 198 

 visibility of chromonemata, effect on, 32 

 Toxopneustes, eggs of, 135 

 'Tr. Pr.', of Mirsky, 48 

 Trabants, 64 

 Tradescantia 



chromosomes of, 100 



nuclei, DNA content of, 34, 37 



pollen mother cells, 94, 115, 136, 138 



cultivation of, 75 

 pollen tubes, 193 



staminal hair cells, 72, 92, 135, 194, 198 

 mitosis in, 70, 71-74, 85, 88, 93, 146- 

 147, 184, 191, Plate V 

 Trephocytes, 170, 171 

 Trephones, 163 



secreted by leucocytes, 170 

 Tricitonucleic acid, 6 

 Tricitum, roots of, effect of paradichloro- 



benzene on, 198 

 Trillium 



anaphase chromosomes 4-stranded, 93 

 negative heterochromatin in, 135-136 

 pollen mother cells, 75 

 Triton, 145 

 duration of mitosis in, 85, 87, Plate VII 

 germinal vesicle of, 52 

 trivalents, position in, 117 

 Triturus, egg of 

 cortical changes in cleavage, 141, 142 

 oocytes of, nuclear membrane, 52 

 Trivalents, position of in metaphase, 117, 



125, 126 

 Trypaflavine, 196 



effect on Frog's sperm, 143 

 Trypsin, 103 



effect on nucleases, 8 



inhibitors of, use in digestion of DNA, 10 

 Tryptophane, 48, 103 



absorption spectrum of, 11, 12 

 Tumour cells, 134, 151, 164, 170 

 chromosome size in, 62, 63 

 culture, in, sensitive to podophyllin, 192 

 phase-contrast cinematography of, 71 

 postulated oestrogen-like stimulant to 



mitosis in, 169 

 ultraviolet absorption of, 14, 15, 33 

 Turnover rates 

 DNA, of, 5 



dependance of mitotic rate, 1 7 

 RNA, of, 5 

 Tyrode saline, 176 

 Tyrosine, 48, 104 



absorption spectrum of, t i , 12 



Ultra-violet light, absorption in, 9, 35, 106 



Uracil, 5 



Urea, 50 



Urechis, egg of, 139 



effect of pressure on spindle in, 1 38 



Urethane, 185 



as mitotic inhibitor, 191 

 Usnic acid 



cleavage, effect on, 197 



P'* uptake, effect on, 200 



Vacuoles 



contractile, 82, 134 



cytoplasmic, 51 



fibroblasts, in, 20-22 



nucleolar, 40 

 Valence forces, 131 

 Valine, 49 

 Vesicles, chromosomal, 32-33, 138 



in telophase, 80 

 Vicia, 103 



duration of mitosis and interphase in, 82, 



85, 90, 91 

 Viper, 38 

 Virus, 97, 178 



tobacco mosaic, 130, 132 

 Viscosity 



Newtonian, 25 



non-Newtonian, 25 



protoplasmic, changes during mitosis, 

 136-140 

 Vital staining 



mitochondria, of, 23, 24 



transitory, of nucleus, li, 53 

 Vitamins, A, D, 171 



Waring blender, loi 

 Wound healing, 167 



X-chromosomes, 44, 93 



effect of absence of in Drosophila egg, 197 



polyploid nuclei, in, 149, 150 

 X-ray diffraction, 13 



of tactoids, 130, 131 

 X-rays 



absorption histospectroscopy by, 80, 106 



chromosome duplication, and, 94 



diffuse spindle attachment, effect on, 197 



mutagenic chemicals cause similar effects, 

 209 

 Xanthine oxidase, 193 

 Xenopus 



mitochondria of, 22, 23, Plate I 



nuclear membrane of, 52 



oocytes of, nuclear sap in, 33, 48, 49 



Y-chromosomes 



Drosophila salivary nucleus, 45 



effect of extra one in oocyte nucleus, 14, 16 

 Yeast, preparation of RNA from, 3 

 Yolk, formation of, 39, 100 



Z-chromosomes, in silkworms, 42 

 Z^a mais 



mitotic inhibition in, 190 



nucleoli of PMCs, 1 6 

 Zdleriella intermedia, nucleoli and chromo- 

 somes in, 42 

 Zinc 



in alkaline kidney phosphatese, 50 



deoxyribonucleoprotein, in, 50 

 Zygotene, 1 1 1 



232 



