84 ANIMAL METAMORPHOSIS. 



would indicate a plant organism, so the presence of an alimentary 

 cavity, more or less complex, is a fairly constant feature of animal 

 organisation. We may state the case thus : — Ajiimals can take 

 solid food into the body, and there digest it ; and as Huxley says — 

 " The definition so changed will cover all animals, except certain 

 parasites, and the few and exceptional cases of non-parasitic 

 animals which do not feed at all ; on the other hand, it will 

 exclude all ordinary vegetable organisms." 



Plants get their food from the soil, or air, in a liquid or 

 gaseous state, by absorption through their surfaces ; animals 

 obtain theirs from plants, or plant-feeders, taking it into their 

 bodies, and there digesting it. The solvent process in plants, 

 although corresponding accurately with that process in animals, is 

 carried on ontside the body, the resulting matter being afterwards 

 absorbed, so that the carnivorous plants are really included in our 

 summary, only in their cases, the food is animal in constitution, 

 and not derived from either air or soil. 



animal fIDctamorpboeie* 



By J. B. Jeaffreson, M.R.C.S., etc. 

 Plate II. 



Part I. 



THE subject selected for consideration in the present paper is 

 that of Animal Metamorphosis. By the term Metamorpho- 

 sis we understand the series of changes undergone by many 

 creatures after their exclusion from the egg, and before they 

 assume the characteristics of their adult condition ; changes which 

 frequently alter extensively the general form of the individual, or 

 so modify its functions that its appearances and mode of life, at 

 different periods of its existence, are totally dissimilar. 



We are so used to seeing that " the child is father to the man," 

 and that the young of most of the animals with which we are 

 acquainted differ only from their adult representatives in size and 

 some trifling peculiarities, that we are in the habit of regarding it as a 



