330 DROSOPIIYLLUM LUSITANICUM. CHAP. XV 



secretion was accumulated in the course of a day that 

 it ran down the tentacles and covered large spaces of 

 the leaves. 



The glands to which the above named nitrogenous 

 substances and liquids were given did not, as just 

 stated, secrete more copiously ; on the contrary, they 

 absorbed their own drops of secretion with surprising 

 quickness. Bits of damp fibrin were placed on five 

 glands, and when they were looked at after an interval 

 of 1 hr. 12 m., the fibrin was almost dry, the secre- 

 tion having been all absorbed. So it was with three 

 cubes of albumen after 1 hr. 19 m., and with four other 

 cubes, though these latter were not looked at until 

 2 hrs. 15 m. had elapsed. The same result followed 

 in between 1 hr. 15 m. and 1 hr. 30 m. when particles 

 both of cartilage and meat were placed on several 

 glands. Lastly, a minute drop (about -^ of a minim) 

 of a solution of one part of nitrate of ammonia to 

 146 of water was distributed between the secretion 

 surrounding three glands, so that the amount of fluid 

 surrounding each was slightly increased ; yet when 

 looked at after 2 hrs., all three were dry. On the 

 other hand, seven particles of glass and three of coal- 

 cinders, of nearly the same size as those of the above 

 named organic substances, were placed on ten glands ; 

 some of them being observed for 18 hrs., and others 

 for two or three days ; but there was not the least 

 sign of the secretion being absorbed. Hence, in tho 

 former cases, the absorption of the secretion must 

 have been due to the presence of some nitrogenous 

 matter, which was either already soluble or was ren- 

 dered so by the secretion. As the fibrin was pure, 

 and had been well washed in distilled water aftei 

 being kept \n glycerine, and as the cartilage had been 

 soaked in water, I suspect that these substances musl 



