THE BEGINNINGS OF IIFE. 315 



poussent des bourgeons par Tune ou par les deux ex- 

 tremites a-la-fois, et produisent egalement le meme 

 VenicllUum glaucum ' (loc. cit., pp. 340, 342). The fact 

 that so many corpuscles undergo a similar change 

 beneath the same covering glass, that these changes 

 take place in cofpuscles which are so large as to be 

 most easily observed, and that all stages may be de- 

 tected between apparently unaltered milk-globules and 

 the large Fungus-germs into which they are transformed, 

 make these observations absolutely convincing, to any 

 one who has once witnessed them ^ They therefore 

 become typical of many other changes which may take 

 place, but in which all the stages of the transformation 

 cannot be so easily watched 2. 



1 And yet, in opposition to the investigations of M. Turpin, extending, 

 as he says, over more than six weeks, and the positive statements which 

 he was able to found upon them, one of our most influential authorities 

 on such subjects is content to offer the following somewhat loose 

 criticism : — ' Without laying too much stress on the difficulty of fol- 

 lowing up the development of a single globule amongst a multitude, 

 there can be no reason why spores of Penicillium, or at least particles 

 capable of reproducing it, should not be present in the milk as well as 

 the o'idium in diabetic urine. And though the true spores are of con- 

 siderable size, it is more than probable that many moulds — as, for 

 instance, such as grow on paste, decaying meat, vegetables, &c. — assume 

 on their first development a form very different from that of the full- 

 grown plant.' (' Introd. to Crypt. Bot.,' Berkeley's, p. 260.) 



^ Since the above has been in type, I have ascertained that heteroge- 

 netic transformations may be much more easily seen in a minute portion of 

 Neufchatel cream-cheese. By placing a portion, about the size of a pin's 

 head, upon an ordinary glass slip, moistening it with distilled water, and 

 spreading it into a thin film, the changes which it undergoes can be 

 readily watched. When kept in this moist uncovered state in a damp 

 chamber at a temperature of 65° F, I have found that at the expiration 



