310 PHYSIOLOGICAL BOTANY. 



Gothe as the discoverer of the exponential method." Why 

 does the author, who is remarkably clear-headed, make 

 use of such expressions as these ? Can a body be con- 

 sidered as in a state of formation when we are ignorant 

 of what it is destined to become ? Must we not always 

 commence with the defining method, and then pass to 

 the exponential ? Have not all natural philosophers done 

 so ? Were not the species of frogs and salamanders first 

 determined ? Was this not necessary to avoid confusing 

 the metamorphoses which they undergo in their early 

 stages ? Again says the author : " Some of our philoso- 

 phers assert that it is necessary for us to assume well- 

 defined limits between plants and animals, since without 

 this assumption science would degenerate into fantastic 

 mysticism." Now this is not exactly the case. 



But when I distinguish plants from animals, I must 

 know by what means I do so. Ehrenberg adopts the 

 character of an animal originally proposed by Blumenbach, 

 the presence of a cavity (stomach), from which the 

 entire being is nourished. This is not the place for dis- 

 cussing whether this is correct or not. Ehrenberg would 

 ask, has Hcematococcm a stomach ? No : then it is not 

 an infusorial animal, but a portion, the seed of one of 

 the Algae, which must undergo several metamorphoses 

 before it is perfectly developed. For the same reason, 

 the spore of Ectosperma (Faucheria), with its cilia, is not 

 an animal, but, as Unger correctly states, in a state of 

 transition to the animal condition ; that is, as far as we 

 can judge from its possessing motion. Observations 

 and experiments, such as those detailed by Kiitzing and 

 Elotow, are of great importance ; but I should prefer a 

 somewhat simpler path than the latter has followed. 



On the Cells containing Spiral Fibres in Fungi. Bot. 

 Zeit., 1844, p. 369. The author, Professor von Schlech- 

 tendal, after reporting what has already been stated 

 upon this point by Roman. Hedwig, and subsequently 

 Corda, details his own observations upon some dried 



