254 



Prof. H. C. Bastian on Heterogenetic [Mar. 21, 



A few days after having made the infusion, the changes in which have 

 just been described, I prepared another with a portion of the same sample 

 of hay. This second infusion, however, was made with water at a tempe- 

 rature of 158° F., which was maintained at this heat for two hours. After 

 nitration it was placed in a similar vessel, and allowed to stand side by side 

 with the other infusion. On the third day, embryonal areas of various 

 shapes and sizes were seen in the firm pellicle which had formed upon the 

 surface*. These areas were distinguished by their whitish, refractive ap- 

 pearance from the slightly fawn-colour of the contiguous unaltered pellicle. 

 Particles of some kind were obscurely seen within the . refractive proto- 

 plasm, and on the following day many of the areas, which had increased in 

 number, showed signs of commencing segmentation. This process went on 



Fig. 5. — Segmentation of Embryonal Areas into Fung us -germs. ( X 1 670.) 



a. First stage of differentiation. 



b. Area almost homogeneous and refractive. 



c. First stage of segmentation. 



d. Area showing more complete segmentation. 



e. Area in which homogeneous refractive products are being converted into 



brownish vesicular Fungus-germs. 

 /, /, /. One form of germ in different stages of development. 

 g,g', g". Another form of germ in different stages of development. 



comparatively slowly, and two or three days elapsed before the segmenta- 

 tion was completed. But at last some of the areas were wholly resolved 

 into a number of colourless, homogeneous, and highly refractive spherules, 

 about -oVo" m diameter. Some areas seemed to remain in this condition for 

 two or three days longer, whilst in others the products of segmentation 

 began to undergo change almost before it was completed. In each case, 

 however, the modification was of the same kind, and consisted in a gradual 



* The daily temperature being about 60° F. 



