Latham : Stimulation of Sterigmatocystis 341 



to a lesser extent were grown on the nutrient solutions prescribed 

 by Pfeffer * and designated as A and C in the first paper on the 

 subject by Richards^f the cultures confined in an atmosphere of 

 chloroform of known or approximately known value and the effect 

 upon dry weight of the crop, economic coefficient and acid coef- 

 ficient noted. 



The work 



laboratory 



College during the years 1904 and 1905 under the guidance of 

 Dr. Herbert Maule Richards, to whom his student is much 

 indebted for his kindness and interest. To the New York Botan- 

 ical Garden many thanks are due for extending the privileges of 

 the library. 



To grow the fungi, small dishes 70 mm. in diameter and 30 

 mm. deep were used. These, In all series following IV, were 

 of the non-sol glass of Whitall, Tatum & Co. Each culture dish 

 rested on two strips of glass over a half Petri dish containing 40 

 c.c. of a 10 per cent KOH solution. The Petri dish in turn sat 

 upon a ground-glass plate. On glass strips laid across the cul- 

 ture dish was supported a small watch glass to receive the chloro- 

 form. In operating, each dish was arranged as described and all 

 covered by a bell-jar which was ground down on to the glass 

 plate in a glycerine-gelatine seal. After the seal had hardened, 

 amounts of chloroform calculated to the capacity of the jars — 

 due allowance having been made for the solids and liquids within 



were run in through the neck which was at once closed with a 

 rubber stopper. It Is possible In this way to regulate the supply 

 of chloroform vapor with tolerable accuracy, for the placing of the 

 stopper in position occupies but a moment and relatively little of 

 the chloroform can volatilize and escape. Moreover, the seal at 

 the base of the jar is sufficiently strong to be proof against any 

 small pressure generated by the vaporizing liquid. 



In manipulation, the usual precautions were observed. The 

 culture dishes, before each using, were soaked in dichromate 

 cleaning solution, washed, rinsed in distilled and redistilled water 

 and sterilized in hot air at 1 00°- 120^ C The bell-jars were 



r 



* Pfeffer, W. Ueber Election organischer Nahrstoffe. Jalirb. Wiss. Bot. 28: 



205. 1895. 



fL. 



c. 



