﻿CURRENT LITERATURE 



539 



ive in the production of oogonia. Sucrose is probably not used by species 

 of Saprolegnia or Achlya. Phosphates in the culture solution tend to increase 

 the reproductive capacity of the fungus— J. M. C. 



Life forms of New York vegetation —Ratjnkiaer has devised a method 

 of classifying plants according to the way in which they pass the unfavorable 



known as a "biological spectrum," the flora of one region may be compared 

 with that of the world as a whole. This journal has commented favorably 

 upon these methods, 2 '' but they have been neglected by American workers as 

 a whole. It is therefore pleasing to see them applied by Taylor 2 * to the flora 

 of New York. From the very nature of such investigations, the results will 

 be more significant and valuable as a larger number of similar studies are made. 

 Compared with the normal spectrum, the New York flora is higher in percent- 

 ages of aquatics, geophytes, and hemicryptophytes, and somewhat lower in per- 

 centages of chamaephytes and phanerophytes. No other area to which this 

 method of analysis has been applied has shown such an abundance of deep- 

 rooted perennials of the bulb and rootstock type, here termed geophytes. 

 This is to be correlated with and is partly explained by the large proportion 

 of monocotyledons in the portion of the pine barrens included in the area 



census of individuals rather than one of species, different and probably more 

 significant comparisons would result— Geo. D. Fuller. 



Disease resistance.— Jones and Oilman 26 have published a very sugges- 

 tive bulletin upon the control of the cabbage disease known as "yellows," 

 caused by the soil fungus Fusarium conglutinans. It seems that on badiy 

 infected or cabbage-sick soil the loss ordinarily ranges from 50 to 95 per cent. 

 Experimental work through five summers seems to justify the conclusion that 

 no method of soil, seed, or crop treatment offers any hope for the control of the 



by selection has given such promising results that "full reliance can be placed 

 in it as a feasible method for the practical control of this malady." Control of 

 various commercial varieties of cabbage showed that there are marked differ- 

 ences in susceptibility among them, and advantage is taken of this fact to dis- 

 cover a Fusurinm-TtmXaxiX strain. The method employed has been based on 

 the observation that even in the worst diseased fields in the autumn there are 

 occasional sound heads, and these have been selected for pedigree culture. 



2 «Bot. Gaz. 44:393- i9°7; 51:309-310- *9"- 



2 * Taylor, Norman, The growth forms of the flora of New York and vicinity. 

 Amer. Jour. Bot. 2:23-31. 1915. 



* Jones, L. R., and Oilman, J. C, The control of cabbage yellows through disease 

 resistance. Agric. Exp. Sta. Univ. Wisconsin Bull. 38. pp. 70. Jigs. 23. 1915. 



