542 EXPERIMENT STATION RECORD. 



to form a layer of calciuin cnrbonalc over it. Tlu- (•rcosol-cjilcium is easily 

 soluble in wiiter. 



Impreg-nation of beech ties with copper arsenite, X. von Lokknz (hniniif)- 

 nicniiitj roil liiirliciimliiri Urn itiit uisciiiiisdunin K iiiifcroxifd. Mruiin. I'JO'.K pp. 

 J). — Noted from another source (K. S. II.. 121, p. did). 



The use book: Grazing ([/. /S. JJciil. .l.'/r.. Forest Nc/r.. Hi ID. pp. iS'/). — 

 This is the fourth revision of that portion of the regulations and instructions 

 for the use of the National Forests (E. S. !{., lit. jt. 147) relating to the grazing 

 of live stock, and took effect JanuMry 1. 1910. 



DISEASES OF PLANTS. 



Researches on fungi, A. II. It. Bim.i.kk y London. Xcw York, lioinhnij, and 

 Calcutta, J909, pp. XI +287, pis. 5, figs. S3).— Part I of this work includes in- 

 vestigations of the production, discharge, and dispersal of the si)ores of the 

 Hynienouiycetes treated botanically and physically. Part II is a similar treat- 

 ment of the Ascomycetes. The following is a summary of a few of the more 

 important results obtained : 



The spores of the Hymenomycetes are very adhesive when freshly liberated. 

 Paraphyses are useful as spacial agents. Direct sunlight injures the vitality 

 of the dry spores of certain species. Spores falling from a fruit body swspended 

 in a closed beaker can be seen, in clouds or individually without magnification 

 by using a concentrated beam of light. Fruit bodies of corky or leathery con- 

 sistency are xerophytic, for when revived after drying, they resume the func- 

 tion of discharging spores; the spores liberated are viable. 



The four spores on each basidium are forcibly and successively discharged. 

 Each spore is shot out horizontally from its sterigma to a distance of about 

 U.l mm., with an initial velocity of 40 cm. per second, but is rai)idly checked 

 by the resistance of the air, in consequence of which the spores describe a 

 sharp curve called the " sporabola " and then fall vertically to the ground if 

 in still air. The specific gravity of certain species ranges from 1.02 to 1.21. 

 The falling spores are claimed to be electrically charged. 



The parasitism of. fungi, B. W. Schmidt (Ztschr. Pflanzcnkrank., J!) (1009), 

 No. 3, pp. 1,!9-l'iS, figs. 7). — An attempt is made to prove that the entrance of 

 the germ tubes of parasitic fungi into the tissues of their hosts is due to 

 chemotropic influences. Experiments were conducted with artificial cells ar- 

 ranged as follows : 



A sack with walls made of celloidin was, by means of a glass rod, so sus- 

 pended inside of a flask, on the bottom of which was a thin layer of gelatin, 

 that the bottom of the sack was a slight distance from the gelatin layer. The 

 sack was filled about two-thirds full of plum extract gelatin and the whole 

 apparatus sterilize^I. Spores from pure cultures of the pear Phyllosticta were 

 then placed on the gelatin layer at 1.5, 2.5, 3.5 cm. from the sack, the flask 

 closed and the growth of the 3 resulting colonies observed. 



The colony nearest to the sack at the end of 11 days had reached the bottom 

 of the sack, and by the end of 23 days the lower portion of the sack was cov- 

 ered with a dense growth of hyphte, many of which had penetrated through the 

 celloidin walls and into the nutrient solution within. The other colonies did 

 not show any apprecial)le turning of their growth zones toward the sack. The 

 fungi in the sack continued to grow until fruit bodies were formed. 



The author claims that the celloidin walls represent cell walls; the nutrient 

 solution, the chemotropic cell substance; and the growth toward and through 

 the celloidin walls, the infection germ tubes of fungus spores when they first 



