76 Hydration and Growth. 



was imminent, and when the first trials were made I had two main 

 purposes in mind : first, to ascertain whether or not foreign substances 

 could be introduced into ovaries in such manner as to affect the ovules 

 with a minimum of traumatic effects, so that the ovaries might reach 

 maturity; and secondly, to ascertain whether or not such changes 

 could be produced in an early stage of sexual specialization before the 

 development of the embryo-sac or after the union of the sexual ele- 

 ments in fertilization. The value of the results was much lessened by 

 the fact that the direct effects of the reagents could not be identified. 

 After some difficulty the actual diffusion of the liquids in the ovaries 

 was ascertained by substituting dyes for the salt solutions, but there 

 still remains to be determined the nature of the action of the reagents 

 on the cell colloids. 



Fio. 10. — Tracing of auxographic record of swelling of plates consisting of 6 parts agar, 2 parts 

 mucilage of Opuntia, 1 of gelatine, and 1 of bean protein, in distilled water, A; rain water, B; 

 well water, C; and a soil solution, D. 



The first step in such an examination would naturally be the measure- 

 ment of the hydration effect. Plates of agar 90 parts and bean pro- 

 tein 10 parts, 0.25 mm. thick, were swelled to ascertain the possible 

 imbibition effects. A series in the dark room at 15° to 16° C. gave the 

 following measurements of expansion: 



Table 68. 



p. ct. 



Distilled water 1,220 



Methylene blue 860 



Iodine, sat. solution in distilled water 1 , 080 



A third reagent used in the later series of ovarial treatments, zinc 

 sulphate, was tested in the concentration of 1 part in 10,000 (0.00034 M) 

 in comparison with distilled water and hydroxid on sections of agar- 

 bean albumin. The swellings were as below : 



Table 69. 



p. d.. 



Distilled water 1,388 



Zinc sulphate, 0.00034 M 833 



Sodium hydroxid, 0.01 M 194 



The characteristic high rate of swelling of agar-albumin is exhibited, 

 the swelling in the hydroxid being but one-seventh that in water. The 



