540 THE BEGINNINGS OF LIFE. 



origin of some Tardigrades, and I have already in my 

 possession much convincing evidence, derived from per- 

 sonal observation, that some water Mites or Acari, and 

 also the ciliated embryos of Naides, may be produced 

 by a direct transformation of masses composed of 

 the protoplasm and chlorophyll of Nitella. 



Thus, in addition to representatives of each of the 

 groups belonging to the class Scolecida, there is already 

 reason to believe that we may at once attain, by 

 heterogenetic transformations of the most startling 

 character, to some of the lowest Annelida and also 

 to some of the lowest of the Arthropoda. And whilst 

 the actual origin of the representatives of these great 

 groups of the Animal Kingdom would thus be laid bare 

 by researches conducted upon fresh-water forms of life, 

 marine products remain as yet wholly unexplored from 

 this point of view — and consequently whole mines of 

 wealth are probably awaiting the diligent student in 

 these fields of research. On the other hand, how much 

 remains to be ascertained concerning some of the 

 lower representatives of the Vegetable Kingdom ! To 

 what extent, if at all, is a heterogenetic mode of origin 

 possible amongst Ferns and Club-mosses? To what 

 extent does it prevail amongst Mosses, Liverworts, 

 and other allied Cryptogams ? These are some of the 

 numerous problems which remain to be decided by 

 future workers. 



