Books and Current Literature. 



185 



constituent of the living substance; normal life, according to 

 the author, being possible only when the necessary salts combine 

 with the colloids of the plant cell in a definite relation. 



R. E. Fries, experimenting on Spironema jragrans, a Mexican 

 plant of the Spiderwort family grown in the Botanical Garden 

 of Upsala, has found that this plant, in general like Mariea, 

 Cordia and certain orchids, is characterized by simultaneous 

 blooming of different individuals at intervals of from one to ten 

 days. When an individual was kept in very faint light, or ex- 

 posed to ten degrees lower temperature, the intervals during 

 which blooming was wholly interrupted were lengthened for 

 this particular individual, but when like conditions were restored 

 the typical synchronism of different individuals was again estab- 

 lished. This synchronism of blooming on the part of different 

 individuals is believed by the author to be of much impor- 

 tance in connection with pollination. 



Burgerstein, in the Ber. d. deutsch. bot. Ges., presents an 

 account of the influence of light of different refrangibilitv on the 

 development of fern sporangia. Some 25 species of ferns were 

 kept under observation in a greenhouse. Yellow and blue glass 

 was employed with the result that under the influence of the 

 blue rays the prothallia were formed from a few days to some 

 weeks later than under the action of rays of less refrangibilitv. 



From studies of Burck reported in the Revue generale de 

 botanique it appears that in Stellaria media dehiscence of the 

 anthers is dependent on the presence of nectaries at the base of 

 the stamens. In this and various other species water is drawn 

 from the stamens by osmotic action on the part of nearby 

 tissues containing much glucose. In addition, then, to the secre- 

 tion of nectar as an aid to fertilization by insects, and the pro- 

 duction of reserve sugar to be used in the development of fruits 

 and seeds, the nectaries of certain species appear to play an im- 

 portant part in determining dehiscence of the anthers independ- 

 ently of the hygrometric condition of the atmosphere. 



The views of von Ihering set forth a decade and a half ago, 

 according to which the northern parts of South America were 



