INDEX 



727 



87-89; internal causes of, 155-217; 

 kinds of, 17-23; morphological, sub- 

 stantive, meristic, functional, 22 ; 

 meristic, 33-74 ; morphological, 25- 

 29; substantive, 30-32; quantitative 

 and qualitative, 17; nature of, 356- 

 364 ; not notably less in partheno- 

 genesis, 178; through inheritance of 

 modifications, 292 ; units of, 208-213; 

 universality of, 7, 8. 



Variations, due to causes internal to the 

 germ, are transmitted, 348 ; due to 

 external influences, transmission of, 

 348-417 ; due to causes not affecting 

 the germ not transmitted, 416, 417; 

 occur according to the binomial the- 

 orem, 508, 509. 



Varieties, duration of, 544, 545. 



Vigor, often opposed by selection, 



583- 



Vital limits as to light, 244. 

 Vochting's experiments on gravity and 



polarity, 237. 



Wallace on the accessory chromosome, 



636. 



Water, effect of, upon growth, 230-233. 

 Wattles, 46. 



Wayland, originator of plum, 133. 

 Weeping varieties, 112. 



Weismann, experiments with butter- 

 flies, 262-264 5 on death point, 202 ; 

 on germinal selection, 214 ; on origin 

 of characters, 413, 414; prediction 

 concerning loss of hereditary matter, 

 173, 174; on transmission, 354. 



Whale, variation in digits of, 57. 



Wheat, acclimatization of, 376; influ- 

 ence of locality upon, 222. 



White, Hugh, originator of Clinton 

 grape, 134. 



Whitney, fund for exploration, 302. 



Willow, effect of gravity on growth of, 

 238. 



Wilson, John, originator of blackberry, 

 132. 



Wilson on the chromosome, 634. 



Wing, supernumerary, 4 }, 51. 



Writing with the feet, 286, 287. 



Xenia, 183, 184. 



Young breeders, 675. 



Yucca moth, 105; instinctive acts of, 



388. 

 Yule's formula, 456, 457. 



Zoja, experiments in regeneration of 

 blastomeres, 325. 



