m 



142 



as for illustration, the dangle-berry, {Gaylnssaccia frondosa) in a 

 Massachusetts locality, bore little fruit in 1888, the bloom failing 

 to form, while in 1889, in the same locality the shrubs were ex- 

 tremely prolific. We find excellent illustration of the effect of 



1 Royle. Trans. Linn. Soc. xvii. 563. 



2 Darwin An. and PI. ii. 206. 



3lTort. and Phys. papers, 321. Goodrich, Trans. N. Y. Ag. Soc. 1847, 447. 

 4 Agricultural Science. March, 1889, p. 58. 



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climate in Humboldt's statement that on the slopes of the moun- ^ 



tains of Mexico and Xalapa, at (S'J'J toises of height, the luxuri- 

 ance of vegetation is such that wheat does not form ears ; and in 

 India, Firminger notes quite a large number of plants that rarely 

 blossom or seed, such as Convolvulus tricolor^ Geiini atrosaiigtiiu' 

 eunt^ Hibiscus Rosa- Sinensis, H. liliiflorits, etc. Brandis in his 

 Forest Flora names also the Popnliis alba, Banibusa Balcova^ 

 etc., and Seemann in the Feejee Islands the Dioscorea alata. Such 

 instances could be almost indefinitely extended. A correlation 

 between tuber bearing and seedhig also seems to exist. Thus the 

 Agave vivipara^ when grown in rich soil in India invariably pro- 

 duces bulbs, but no seed, while on a poor soil and under arid 



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conditions the opposite result occurs/ The sweet potato in r 



China, according to Dr. Fortune,^ never yields seed ; in our re- 

 gion the sweet potato never blossoms, or if at all very rarely, yet 

 in Alabama it blossoms, but, as Dr. Newman writes me, when 

 forwarding the bloom, that he had never knpwn seeds to be 

 formed. The potato w^as noted by Knight-^ as having varieties 

 that do not bloom, and at the present time the majority of our "^ 



cultivated varieties, while blooming freely, yield no fruit or seed. 

 The sugar cane rarely seeds, and Darwin quotes testimony that 

 it never seeds in the West Indies, Malaga, India, Cochin China 

 or the Malay Archipelago, yet recently at Barbadoes sugar cane 

 has seeded and the seed has yielded seedlings^ A most inter- 

 esting case of barrenness has come under my own observation at 

 Nonquit, Massachusetts, where a gold-striped form of Spartina 

 cynosuroidcs has been sterile for two years, while the ordinary 

 green form alongside has seeded abundantly. Hybridity may 

 also be ascribed as a cause, and Darwin cites a number of in- 

 stances, and quotes Kolreuter as expressing astonishment that 



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