522 EXPEEIMEXT STATION EECORD. [Vol. 41 



mauasrement in vogxie is sure to follow. Wliere the nesrative indicators ai'e 

 crowding out tlie more permanent and desirable species, remedial measures 

 should be adopted with a minimum loss of time. Since range depletion is due 

 chiefly to too early cropping or to overgrazing, the application of the deferred- 

 and-rotation grazing system, coupled with a correct estimate of the carrying 

 capacity of the range, may be relied iipon fully to revegetate the lauds where 

 enough plants of desirable species are found for seed production. 



Botanical survey [in India], H. G. Carter {Anu. Rpt. Bd. Sci. Advice India, 

 1P16-17, pp. S2-S^). — This contains an account of studios extending the lists 

 of known plants in portions of India, with notices of recent publications on cer- 

 tain groups. 



Agricultural botany [in India], A. Howard {Ann. Rpt. Bd. Set. Advice 

 Iiulid. 1916-17, pp. 35-^3). — A discussion of this phase of economic botany 

 includes, besides mention of technical publications, reports on the improvement 

 of crops, among them cotton, rice, sugar cane, wheat, jute, indigo, fruit, and 

 chilies. Root nodules and soU aeration also receive notice. 



Forest botany [in India]. R. S. Hole (A)in. Rpt. Bd. Sci. Advice India, 

 1916-17. pp. -}-J-^6'). — This report, which is complementary to that noted above, 

 deals with soil aeration, forest grasses, sissoo (Dalbcri/ia sis.soo), root disease 

 (Forney iv.cidus) and spike disease of sandal, with mention of descriptive lists 

 and papers on the systematic botany of this region. 



Evolution through nonnal diversity, O. F. Cook {Jour. Wash. Acad. Sci., 9 

 {1919), No. 7, pp. 192-197). — The author makes reference to a paper by Meehan 

 published in 1894 (E. S. R., 6. p. oS9) iu which attention is called to observa- 

 tions by himself, confirming his records extending back about 25 years and 

 tending to show that there is in the plant in question {Impatiens fulva) innate 

 power to vary coexistent with the species itself, independent of any condition? 

 of environment. This definite recognition of normal diversity is referred to 

 on account of the historical interest. Diversity being accepted as a normal 

 and general condition in species, evolution is seen as a process of integration 

 and differentiation of characters, the two essential conditions of evolutionary 

 progress being normal diversity (heterism) and free intercrossing of lines of 

 descent ( symba sis t . 



The symbiomorphoses; recent studies on asexual hybridization, L. Daniel 

 {Rei: G^n. Bot., SO {1918), No. 359, pp. 367, 36S).— In the resume of this work 

 by L. Defoiir, it is stated that the tuithor has given attention to certain modi- 

 fications of plants observed to arise in consequence of grafting. These have 

 been called symbiomorphoses, of which two classes or cases are distinguished, 

 namely those arising when different genera or species are grafted and those 

 arising when grafts are made between varieties. The author reaches the gen- 

 eral conclusion that in a given graft one may encounter variations of diverse 

 origin. These symbiomoi-phoses are almost always resultants of numerous 

 factors which may be physical, chemical, or physiological in character. 



It is considered as impossible at present to distinguish the precise action of 

 this or that morphological or genetic factor on account of the extreme com- 

 plexity of the result. 



Underground runners, E. Warming {K. Dan^^ke Ti<Jensk. Selsk. Skr., Natur- 

 ridcn.^k. og Math. Afd., S. so:. 2 (191S). No. 6. pp. 295-37S. figs. -}J).— This con- 

 tribution contains a definition and discussion of several types which ai*e dis- 

 tinguished of plaglotropic shoots. 



Natural grafting of branches and roots. W. DALLiiiORE {Roij. Bot. Gard. 

 Keir. Bui. Misc. Inform., No. 9-10 {1917). pp. 303-306, pis. ;?>.— Examples of 

 natural grafting occurring iu cases observed, either above or below the surface 



