50 Mr. H. J. Carter on Amoeba princeps 



former to present a plant- or fungus-like constant figure, which, 

 in the Myxogastres, is continually varying up to the moment that 

 they end in a rapid consolidation of their fructifying ingredients. 

 So in Mucor, the germinating cells of the peridiole rapidly pass 

 from a colourless plastic form into a hard, dry, dark brown 

 capsuled one; while in Achlya, or the aquatic form of Mucor, 

 the capsule is colourless, and so evanescent that the young are 

 put forth from the peridiole almost viviparously. It is easy, 

 therefore, to see here why the germs of the aerial form are 

 wrapt up in a dense capsule, while those of the aquatic one do 

 not need any. 



But I am straying away from the point, although, from what 

 I have above stated, it will now, I think, be satisfactorily seen 

 that j^thalium, for the greater part of its life, lives like Amoeba, 

 and that, although there may be a little difficulty in proving 

 that the foreign particles seen in the great masses of jEthalium 

 have been taken in for food, still Pythium, which has a kind of 

 mycelium and is thus intimately allied to Achlya (which, again, 

 is but an aquatic development oi Mucor), does undoubtedly take 

 in crude material for food identically with Amoeba. 



Whether the Myxogastres are entitled to the new name of 

 " Mycetozoa" (proposed for them by M. A. de Bary) under these 

 circumstances, or not, I leave others to determine. There are 

 no absolute lines of demarcation here more than anywhere else, 

 and therefore common sense, aided by progressive knowledge, 

 must be appealed to for decision also here as well as else- 

 where. 



Although not immediately bearing on the subject, I would 

 just revert to the statement I have made respecting the light 

 which the study of j^thalium throws on the behaviour of the 

 protoplasm of the plant-cell; for there is yet another point to 

 be considered, viz. how does the protoplasm obtain an external 

 communication so as to produce materials which are found out- 

 side the cell-wall and keep up a communication alone with the 

 external world, as in the unicellular Algae, or when in combina- 

 tion with other cells, as in the plant ? This important question 

 seems to receive solution from M. Garreau^s observations, who 

 states that there are filaments of the protoplasm which pass from 

 the primordial membrane through holes in the cell-wall*; and 

 if this be confirmed, it will lead to such a chain of explanations 

 in the development and habits of the vegetable cell, separate and 

 in combination, as has for some time past been unparalleled by 

 any other similar discovery. 



* Ann. Nat. Hist. vol. x. p. 43 (18G2); translated from Ann. des Sc. 

 Nat. 1860. 



