MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 27 1 



elongation in darkness. Tulips were found to offer as well-marked 

 color of flowers in etiolated plants as in those cultivated in light. 

 Sachs removed the flower buds and fruits from a well-grown speci- 

 men of Nicotiana rustica and placed it in complete darkness, with 

 the result that two inflorescences were developed on etiolated 

 branches about ii days later. The earlier flowers developed in 

 these inflorescences were yellow, but otherwise of normal appear- 

 ance. Self-fertilization ensued and capsules of a size above the 

 average were formed, the seeds taken from which germinated when 

 placed in the soil. He states, however, that the calices of the lower 

 flowers of the etiolated inflorescences were green from the influence 

 of illumination received before the plant was placed in the dark 

 chamber ; hence the flowers did not undergo their entire development 

 in darkness. Scapes of Hyacinthus orientalis^ Tulifa Gesncriana 

 and Ij'is pitniila were seen to attain a length of three times the nor- 

 mal on bulbs sprouted in darkness. In Crocus vermis, on the other 

 hand, the scape remained of a normal length and an excessive elon- 

 gation ensued in the basal portion of the perigone tube. Sachs cites 

 Tuli'pa, Iris, Hyacinthus and Crocus as examples of plants in which 

 the flowers are formed in buds deep in the ground, consequently in 

 darkness, and that flowers of this class can consequently carry on 

 complete development in darkness without ever being exposed to the 

 full influence of sunlight. In this however, a disregard is shown for 

 many facts bearing upon the case. In the first place it is by no 

 means conclusive that the tubers of these plants are in complete 

 darkness when in place in the soil under natural conditions. Even 

 if completely excluded from the effects of direct illumination, it is to 

 be seen that the formation of the flowers in the season previous to 

 the one in which they open, takes place while some of the organs, 

 such as the leaves, are exposed to light, and that the full stimulating 

 effect of this partial illumination doubtless exerts a marked effect 

 upon the young flowers. It was shown in my own experiments 

 that Arisaenia and similar forms did not develop flowers when the 

 plant was confined in darkness for successive seasons, although 

 ample food-material was present. Brassica, Tropacolnm, Papaver, 

 Cucurbita and others, are given by Sachs as constituting a class 

 of plants in which the flowers will not open if deprived of illumina- 

 tion at a time beginning with the earlier stages of the flower buds. 

 The normal blooming of such flowers when confined in darkness 



