Dii. Wallich_, on the Polycystina. 
63 
Now, subscribing as 1 do^ in the fullest sense, to the 
doctrine that we must look to the structural and physiological 
conditions of the animal alone for those characters on which 
we are to base our primary subdivisions, it would,, indeed, be 
somewhat singular that I should have arrived at results 
differing materially from those arrived at by Dr. Carpenter, 
were it not the case that in nearly every instance in which 
our opinions come into collision, his deductions are based 
on data furnished by the observations of others, and not 
on his own personal experience. It is true, moreover, 
that our respective estimates of the value of certain 
characters also differ. But even this admits of explana- 
tion, inasmuch as the characters which I regard as sur- 
passing in physiological as well as structural importance 
those selected by Carpenter, and on which I principally rely 
for the establishment of my system, are, in a great measure, 
new and original. It will be seen, however, that I have pro- 
fited by his teaching in regarding the animal of the For ami- 
nifera as belonging to the simplest Ehizopodal type j whilst, as 
established by him before the really complex nature of Amoeba 
was pointed out by me/^ this Rhizopod and its allies must be 
regarded as belonging to that type which is the most highly 
developed. 
Having made these prefatory observations^ and in order 
to admit of more ready comparison, I now submit, for the 
approval of those interested in the subject, a tabular view 
of the Hhizopodal families, arranged in accordance with 
the gradual evolutions of those organs which are held by me 
to constitute the only trustworthy indices of physiological 
and structural progress. 
"3. LOBOSA. — More complete differentiation of tlie protoplasmic sub- 
stance into endosarc and ectosarc, the former being a slightly viscous gra- 
nular liquid, and the latter approaching the tenacity of a membrane ; a 
nucleus and contractile vesicle; pseudopodia few and large, being in reality 
lobose extensions of the body, which neither ramify nor coalesce, having 
well-defined margins, and not exhibiting any movement of granules on the 
surface, the circulation in their interior being entirely dependent on the 
changes of form which the body undergoes as a whole." — Loc. cit. supra^ 
pp. 466-7. 
* 'On an undescribed Indigenous Form of Amceba,' by G. C. Wallich, - 
M.D., 'Annals and Magazine of Natural History,' April, 1863. "Eurther 
Observations" on the same subject, op. cit. for May and June, 1863. "On 
the Yalue of Distinctive Characters in Amceba," op. cit., August, 1863. 
" Further Observations on the Distinctive Characters and lieproductive 
Phenomena of the Amoeban lihizopods," op. cit., November, 1863. "Fur- 
ther Observations" on the same subject, op. cit., December, 1863; and, 
lastly, " On the Extent and some of t he principal Causes of Structural Va- 
riation among the Difflugian Hhizopods," op. cit., March, 1864. 
