89 



examples h.ive been described by Milde, Luerssen and others, 

 occurring especially on young plants producing spores for tlie 

 first time. 



Onoclea Striithiopteris is said to occupy a high place among 

 vascular cryptogams as regards the variety of leaf development, 

 producing three different kinds, viz, : "Niederblatter/' or '* Cata- 

 phylla/' foliage leaves and fruit leaves. The '* Cataphylla " have 

 been proven by the author, in other cases, to be transformed 

 foliage leaves, and the same fact is confirmed by the stunted 

 blade of the cataphyllum which is visible to the naked eye. 

 Therefore, the structure of this plant is reduced to a much simpler 

 matter than appearances would indicate. The plant forms only 

 one kind of leaf-rudiment, and this is that of foliage leaves from 

 which, according to certain fixed influences, a certain number are 

 developed into cataphylla, certain others into fruit leaves and the 

 remainder into foliage leaves. 



This simple experiment is only one from a long list of morph- 

 ological investigations carried on by the author, who is best 

 known to us through his text-book, ''OutHnesof Classification 

 and Special Morphology of Plants.'' It is of special interest, 

 owing to its simplicity, and at the same time the important 

 bearing it has on the subject of plant morphology. — E. L. G. 



Alia Species Asi(E Centralis, — By E. Regel. (Pamph., pp. 

 8vo. 87, 8 plates; St. Petersburg, 1887.) 



This is an enumeration, with descriptions of n^\x species and 

 varieties of the genus Allium, as represented in Central Asia, 

 with full localities of the specimens examined. It includes 138 

 species, most of them restricted in distribution to the region. A 

 conspectus of the species precedes the main portion of the work, 

 five sections of the genus being recognized. Twenty-nine of the 

 species are represented on the plates, which are excellently done. 



071 the Present Position of the Question of the Sources of the 

 Nitrogen of Vegetation — Preliminary Notice, — By Sir J. B. 

 Lawes and J. H. Gilbert, LL.D. (Proc. Royal Soc, xhii., pp. 

 108-116.) 



The question of the source of nitrogen in plants has long 

 been a subject of discussion and experiment at the several 

 centres of study of agricultural chemistry, and the results reached 



