160 Dr. G. C. Wallich on the Ti/pe 



without tloing violence to the most natural and important of 

 all affinities, namely those founded on the " structural and 

 physiological conditions of the animal alone." 



J3ut, irrespectively of this, were further proof needed of the 

 en-or committed in the separation of these three genera on the 

 basis of diiferences supposed to be more or less constantly 

 observable in the characters of their respective pseudopodia, 

 and the accompanying degrees of " diftcrentiation " said to 

 exist respectively in the external layer of the body, or " ecto- 

 sarc," and the general protoplasmic mass within, or " endosarc," 

 I undertake to show, on l3r. Carpenter's own evidence, that 

 the pseudopodial characters are by no means sufficiently uni- 

 form or sufficiently constant to be depended upon as ordinal 

 distinctions. In short, I hope to make it clear that the terms 

 " ectosarc " and " endosarc " embody a scientific fiction, and 

 that the sole purpose they serve is to mask our ignorance. 

 The sooner, therefore, tliey arc dispensed with, save as con- 

 venient names for the portions of the sarcode-mass that happen 

 for the time being to constitute the external boundary and the 

 internal mass, the sooner may we expect to arrive at an ade- 

 quate idea of the visible characters which distinguish the 

 organism called a Hhizopod *. 



Dr. Carpenter, in defining the characters of the lowest order 

 in his system, namely the Reticidaria, tells us that " in the 

 cases in which the differentiation into ectosarc and endosarc 

 has proceeded furthest, so that that body of the Rhizopod 

 bears the strongest resemblance to an ordinary ' cell ' t (as is 

 the case with Amoiba and its allies), a nucleus may be distinctly 

 traced ; in those, on the other hand, in which the original pro- 

 toplasmic condition is most completely retained (as seems to 

 be the case with Grorm'a and the Foraminifera generally), 

 no nucleus can be distinguished. The same," he says, " ap- 

 pears to be true of the peculiar contractile vesicle, Avhich may 

 be regarded as a vacuole with a defined wall " (^ Introduction 

 to the Study of the Foraminifera,' 1862, p. 14). 



Dr. Carpenter afterwards goes on to make the following 



* For a detailed account of my observations on the Rliizopods gene- 

 rally, I would refer the reader to a series of six papers on the Aiuoiban, 

 Actinophnjan, and hiffiiujian Rhizopods, contriouted by me to the 

 * Annals ' between April 18G3 and March 1864 ; and a paper " On the 

 Pvbjnidina,^' embodying a Classification of the IJhizopodsas a whole, and 

 this family in particidar, which was published in the ' Quart. Journ. Micr. 

 Soc' for July 1865. 



t Bioloffy and physiology are undoubtedly under heavy obligations to 

 the '' cell' doctrine. But it is not saying too much to assert that biolo- 

 gists and physiologists have had a great deal of nasty work cut out for 

 them by the perpetual misapplication and misconception of that doctrine. 



I 



