nS 



SEX AND HEREDITY 



Phyllobates, 70. 

 Phyllomedusa, 68. 

 Pipa, 71, 73. 

 Placenta, 79. 

 Plasmodium, 58, 59. 

 Pollen-grain, 45. 



Pollen-tube, the result of germi- 

 nation of the pollen-grain, 28 : 



41- 42. 



Pollination, the transfer of pollen 

 from the anther to the stigma 

 of the flower, 37. 



Polygonum, ovary of, 42. 



Polvpodium, a Fern, archegonia 

 of, 25. 



Prothallus, the sexual stage of a 

 Fern, which bears the sexual 

 organs, 25. 



Protococcus, 11, 32. 



Protoplasm, the physical basis of 

 life, 2 : necessarily moist during 

 life, 66. 



Protoplast, the whole protoplas- 

 mic body of the cell. 



Protozoa, compared with higher 

 animals, 62. 



Quince, flower of, 28. 



Rabbit, transference of eggs of, 79. 



Recessive, a character of one 

 parent, which is masked in the 

 body of the hybrid by the ex- 

 clusive development of the 

 corresponding character of the 

 other parent, 97. 



Reproduction, complexity of, 53. 



Rhacophorus, 69. 



Rhinoderma, 71. 



Salvia, pollination-mechanism of, 

 40. 



Segregation (Mendelian), the dis- 

 sociation of the parental char- 

 acters or rather of their 

 factors during the formation 

 of the gametes, 95. 



Sexual cells, or gametes, those 

 cells which take part in syn- 

 gamy, 3 : minute and micro- 

 scopic, 8 : of Fucus, 5 : of Man, 

 5. 



Sexuality, 2. 



Shepherd's Purse, seed of, 49- 



Soma, the substance of the 

 animal body apart from the 

 gonad, 64. 



Specialisation of cells, 63. 



Spermatozoid, the microgamete of 

 plants, 4 : of Fucus, 20 : of 

 Fern, 24 : of Zamia, 47. 



Spermatozoon, the microgamete 

 of the higher animals, 82. 



Spontaneous generation, unknown 

 to scientific men, 6. 



Stamens, the parts of the flower 

 which produce the pollen, and 

 ultimately the male gametes, 27. 



Stigma, the receptive surface of 

 the carpel, 28. 



Structural unit, the cell of animals 

 and plants, 2. 



Stylorhynchus, 57, 58. 



Surinam Toad, 71, 73. 



Syngamy, the fusion of two 

 sexual cells, and especially of 

 their nuclei, to form one zygote, 

 3 : in Fucus, 20 : in Fern, 26, 27 : 

 in flowering plants, 30 : in 

 Copromonas, 57 : in Plasmo- 

 dium, 59 : in Stylorhynchus, 58 : 

 in Cyclops, 82 : necessity of, 

 60 : effect in staving off death, 

 61. 



Tissue, a mass of cells of common 

 origin, and showing a common 

 life, composing the body of an 

 animal or plant, i. 



Ulothrix, 12 : ^egetative increase 

 of, 13 : gametes of, 14, 32. 



Unicellular organisms, which con- 

 sist of only one cell, 2. 



