1914] CURRENT LITERATURE 455 



retain it produce males. The author calls attention to the fact that this 



condition is "the converse of that described in most other insects." 



The problem of the relation of chromosomes to sex-inheritance naturally 



becomes more complex as the facts accumulate, and the rather definite results 



obtained from the study of a few forms must be checked by the more general 

 situation. — J. M. C. 



Immunity as a physiological test. — Vavtlov 11 has suggested an interest- 

 ing application of the specific relation that so often exists between a parasitic 

 fungus and its host. He concludes that it has been demonstrated that immunity 

 does not depend upon the anatomical peculiarities of plants, but upon their 

 physiological peculiarities. Of course there is every evidence that in many 

 cases there is some specific relation between a parasitic fungus and the metab- 

 olism of its host. The author suggests that "narrowly specialized" fungi 

 may be used as a physiological test for the recognition of the species and races 

 "in systematic and genetic studies of plants." He illustrates the possibilities 

 in connection with a classification of the races of cereals, claiming that in this 

 way he has been able to detect unsuspected races of wheat and oats. This 

 coupling of the reactions of parasitic fungi with the genetic relationships of 

 their hosts will be more of a promise than a performance until more exact 

 knowledge has developed as to the metabolism of the fungi and of the hosts they 

 are able to infect.— J. M. C. 



A Welsh sand dune area. — Sand dunes historically interesting on account 

 of their position over the site of the castle and buried city of Kenfig have been 

 studied ecologically by Orr, 12 who has just made a preliminary report of the 

 conditions and development of the principal plant associations. The area 

 fringes the Glamorgan coast for 15 miles from Swansea. The pioneer associa- 

 tion is, as usual, one of the Marram grass, followed by Salix repens. The 

 efficiency of Ammophila arenaria as a sand binder seems to have been recog- 

 nized here as early as 1330, when Kenfig made provisions for its protection and 

 preservation. Upon the fixed dunes the final stage in the succession seems to 

 be an association dominated by Pteris aquilina covering considerable areas. A 

 more exact analysis of the factors concerned and a careful delimitation of the 

 associations is promised in a future paper. — Geo. D. Fuller. 



Cordaitean wood from the Devonian 



I ELAND 



have described wood of Cordaitales from the black shale of Indiana. The speci- 

 mens from which the sections were made rested on black shale, and were large 



11 Vavilov, N. L, Immunity to fungous diseases as a physiological test in genetics 

 and systematics, exemplified in cereals. Jour. Genetics 4:49-65. 1914. 



12 Orr, M. Y., Kenfig burrows; an ecological study. Trans. Bot. Soc. Edinburgh 

 26:79-88. 19 13. 



13 Elkins, M. G., and Wielaxd, G. R., Cordaitean wood from the Indiana black 

 shale. Amer. Jour. Sci. 38:65-78. pis. /, 2. figs. 11. 1914. 



