Morphologie. — Physiologie. 37 



phyll even after warm weather sets in, because the necessity 

 !or such formation is no longer present. The inherited tendency 

 to form Chlorophyll is thus counterbalanced by the peculiar 

 action of the environment, which gives the vegetatively produced 

 offspring an abundant foodsupply. As soon as the Stimulus 

 necessary to bring about independent food formation, i. e. 

 dependence upon itself, becomes active, the sucker produced a 

 green leaf. Pierce believes that „the white redwood serves as 

 an index of the relative powers of heredity and of environment, 

 or, more definitely, of heredity and of the influence of, and the 

 power of reaction to, certain Stimuli". He concluded by asking, 

 „May it not be that what we call heredity is really the response 

 to similar Stimuli and combinations of Stimuli occurring in 

 orderly succession in the course of nature?" 



von Schrank (St. Louis). 



Lyon, Florence May, A study of the sporangia and 

 gametophytes of Selaginella apiis and Selaginella 

 nipestris. (Botanical Gazette. XXXII. p. 124—141, 170—194. 

 PI. V— IX. Aug.-Sept. 1901.) 



Fertilization occurs while the spores are still in the 

 sporangia attached to the fruiting spikes, which fall in autumn 

 in 6". apiis but remain until spring, when fertilization occurs, in 

 6". nipestris, seed-like sporangia with well developed embryos 

 bearing cotyledons and root being then formed in this species. 



Trelease. 



Dawson, Maria, On the Economic Importance of 

 Nit ragin. (Annais of Botany. Vol. XV. 1901. p. 511.) 



In Order to determine whether or not nitragin is of 

 practical value in the cultivation of leguminous plants, experi- 

 ments were made with Pisiim sativum (1) on sterilized soils, 

 and (2) on unsterilized soils in the open, 



As the result oi the Examination of about 800 plants grown 

 in various sterilized soils, it was found that the application of 

 nitragin was not benificial. But the pods borne by plants 

 grown on soll to which nitragin had been added were observed 

 to ripen more quickly than those of plants grown on unino- 

 culated soil, an Observation which supports Mattirolo's view 

 that the root-nodules are organs for the elaboration of the albu- 

 minous materials required in the formation of seeds. 



The plants grown on unsterilized soils showed that in- 

 oculation with nitragin caused some increase of weight in the 

 case of gravelly soil: on peat, clay, or loam, inoculation with 

 nitragin proved to be quite useless. 



These unfavorable results as to the value of nitragin lead 

 to the conclusion that the nutrition of Legiiminosae does not 

 merely depend upon the presence or absence of nodule- 

 microbes, but that the relations between these and their host are 



