334 Dr. G. C. Wallich on the true 



circumstances, be accepted as universally applicable, that any 

 doubts can arise as to there being a gradual and not a sudden 

 transition from the confines of one great division of the organic 

 world to the other. But, for reasons already assigned, this 

 transition from the vegetable side is not, and probably cannot 

 be, completed under those conditions which prevail below cer- 

 tain fixed limits of depth in the ocean." 



"If we admit this much as regards the process of shell-deposit, 

 the ground is at once cleared for us ; and, mutatis mutandis, 

 the elimination from the surrounding waters of the elements 

 entering into the composition of body-substance, and their 

 conversion into this substance by a special vital faculty inherent 

 in the protoplasmic mass itself, become at once as easy of 

 comprehension as any purely vital act can be." 



" Lastly, if Bathybius be assumed to constitute the nutritive 

 substance of Globigerina, it follows that, where the largest and 

 purest deposits of that Foraminifer present themselves, there 

 ought to be the greatest supply of the nutritive protoplasm. 

 But, as already shown, this is the reverse of what we find to 

 be the case, inasmuch as amongst the purest Globigerine 

 deposits, where these organisms amount to 80 or 85 per cent, 

 of the entire mass, hardly a trace of gelatinous matter is ob- 

 servable "*. 



But it remains for me to show still more definitely what are 

 Prof. Wyville Thomson's opinions concerning Bathybius and 

 the nutrition of the Protozoa generally. In the preface to his 

 work : The Depths of the Sea,' published three years later, 

 namely in 1873 (Preface, p. viii), Prof. Thomson tells us that 

 " the domain of biology is his own particular province." What 

 he has to say on any such important subject as the attributes 

 of Bathybius ought therefore to command respectful attention ; 

 for the same reason it is indispensable to quote his ipsissima 

 verba on the subject. 



" Prominent among these special groups we find the first 

 and simplest of the Invertebrate subkingdoms, the Protozoa, 

 represented by three of its classes, the Monera, the Rhizopoda, 

 and the Sponges. . . . The German naturalists of the new 

 school, in their enthusiastic adoption of the Darwinian theory 

 of evolution, naturally welcome in these ' Moners ' the essen- 

 tial attribute of the ' Urschleim ; ' an infinite capacity for 

 improvement in every conceivable direction ; and to more pro- 

 saic physiologists they are of the deepest interest, as presenting 



* " On the Vital Functions of the Deep-Sea Protozoa," by G. C. Wal- 

 lich, M.D. &c. (' Monthly Microscopical Journal,' January 1, 1869, pp. 39, 

 40, 41). 



