242 Prof. H. C. Bastian on Hetero genetic [Mar. 21, 



marked and numerous*. The contained Bacteria very soon became notably 

 larger and distinctly loculated — each loculus containing two or three 

 granules ; whilst the jelly-like material was so abundant that every Bacte- 

 riumf was distinctly isolated from its fellows. These particular areas 

 were watched for several days, and were not found to have any tendency to 

 undergo segmentation, although myriads of Monads had been formed in 

 adjacent portions of the pellicle, as well as Fungus-germs which had vege- 

 tated into mycelial filaments and bore numerous heads of spores similar to 

 those of a small variety of Penicillium glaucum. The Bacteria included 

 within these areas seemed to possess too much inherent vigour to lose their 

 own individuality — a supposition which was confirmed by their great in- 

 crease in size and subsequent development. On the fourth and fifth days 

 many were seen which had grown out into minute filaments, resembling 

 what is commonly regarded as Leptothrix, although they also possessed all 

 the characteristics of a miniature fungus-mycelium. 



Thus, then, we may have modified areas in which the contained units 

 flourish and grow, whilst still preserving their own individuality ; or we 

 may have pellucid areas, persisting as such for a certain time, whose units 

 at last undergo a process of molecular fusion and regeneration leading to 

 the production of a segmenting embryonal area from which brown Fungus- 

 germs are produced J. And, lastly, there may be pellucid areas which, 

 almost as soon as they are formed, begin to undergo those changes whereby 

 they are converted into true embryonal areas. 



Many variations exist in the character of these areas in different cases, 

 some of which I will now attempt to describe, as I have lately had an op- 

 portunity of watching all sorts of transitional conditions. 



The pellicle which formed on a filtered maceration of hay during frosty 

 weather (when the temperature of the room in which the infusion was 

 kept was rarely above 55° F., and sometimes rather lower than this) pre- 

 sented changes of a most instructive character. On the third and fourth 

 days the pellicle was still thin, although on microscopical examination all 

 portions of it were found to be thickly dotted with embryonal areas. 



* The daily atmospheric temperature being about 62° F. 



t The corpuscular appearance of some of these bodies was so marked that they might, 

 perhaps, more appropriately be spoken of as Torulce. 



\ During this process the contained Bacteria disappear, and a whitish refractive and 

 homogeneous protoplasm is produced in the place of the jelly and its contained granules. 

 If we turn to the account given of the origin of the " germinal membrane" in the ova of 

 higher animals, we may be struck by the similarity of the phenomena. Mxiller says 

 (Baly's Translation, vol. i. p. 9) : — " It appears, indeed, that the germinal membrane is 

 formed by the attraction and aggregation of the globules of the yolk ; but all parts de- 

 veloped in this germinal membrane are produced by solution of these globules, and con- 

 version of them into a matter in which no elementary particles can be distinctly recognized, 

 and of which the molecules must at any rate be beyond comparison more minute than the 

 globules of the yolk and germinal membrane." The subsequent development of blasto- 

 dermic cells from this mass also agrees closely with what occurs in our embryonal 

 areas. 



