ABSTRACTS 



Authors of scientific papers are requested to see that abstracts, preferably 

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 this issue. 



BOTANY. — Mexican g7'asses in the United States National Herhariuni. 

 A. S. Hitchcock. Contr. U. S. Nat. Herb. 17: 181-389. 1913. 



This paper includes a list of 615 species of Mexican grasses, 23 of 

 which are described as new, represented by specimens in the U. S. 

 National Herbarium. There is a key to the genera, and, preceding 

 each genus, a key to the species. Under each species are given the 

 more important synonyms, the type locality, the range, and an enu- 

 meration of the specimens from Mexico arranged by states. One new 

 genus, Triniochloa, is described. This includes three species, one, 

 from Chihuahua, collected by the author, being new, the others trans- 

 ferred from Avena. One of the latter, the type species, T. stipoides, 

 was first described as Podosaemum and later transferred to Muhlen- 

 bergia and to Avena. 



The more important collections available in the present study are 

 those of Palmer, Pringle and the author, who have explored botanically 

 nearly all the states of Mexico. There are cited also many duplicates 

 of the early collectors, such as Bourgeau, Liebmann, Schaffner, Botteri 

 and Muller. A. S. H. 



PHARMACOLOGY. — Individual variation in the alkaloidal content of 

 belladonna plants. A. F. Sievers. Journal of Agricultm-al Re- 

 search 1 : 129-146. 1913. 

 In a systematic study of the alkaloidal content of the leaves of a 

 large number of belladonna plants, some important facts have been 

 established. The leaves were assayed at five distinct stages of growth 

 from early in May to late in October and the results indicate that the 

 flowering stage is the most advantageous time to pick the leaves. A 

 higher percentage of alkaloids is found later in the season but the leaves 



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