CARPENTER ON THE STUDY OE THE FORAMINIFERA. 325 
“ Types of Structure and Modes of Growth, and the principles to he 
“ followed in their Classification.” 
The general results of the views at which Dr. Carpenter has 
arrived, touching the mutual relations of the leading types of 
Foraminifera having not long since been submitted to the attention 
of our readers, in two articles* which he has himself written for this 
journal, it becomes necessary that we should, on the present occa¬ 
sion, adopt a somewhat different mode of treatment in reviewing the 
more extended summary of them brought forward in the preface and 
first three chapters of the present monograph. 
The name Foraminifera, proposed in J825 by D’Orbigny, is very 
nearly synonymous in its extent with Beticularia, suggested by 
Dr. Carpenter as the best appellation of that order of the class 
Bhizopoda, to which these animals belong. We think, however, that 
he has wisely, both on its title-page and on most occasions through¬ 
out the body of his treatise, seen fit to substitute the older term, 
since, though not in strictness applicable to certain members of this 
group, it certainly is true of most of them, and has besides the ad¬ 
vantage of having been in constant use for a period of nearly forty 
years. 
Although the great majority of the Foraminifera are shell-bearing 
organisms, insomuch that the presence of a testaceous envelope is, 
by most naturalists, invariably associated with their conception of 
these animals, yet the essential characters of the group as a whole 
must rather be sought in the minute structure and physiological con¬ 
ditions of the simple tissue, or ‘ sarcode,’ constituting the principal 
bulk of their bodies. This contrasts with the protoplasmic substance 
of other Bhizopods— 
(1.) In exhibiting a feebler degree of histological differentiation ; 
“ for although the external portion is less granular and coloured 
“ than the internal, and is of somewhat firmer consistence, yet there 
“ is nothing like a definite distinction between ectosarc and end osar c, 
“ so that the departure from the original homogeneity of the sarcode 
“ is here reduced to its minimum. This low grade of differentiation 
“is marked also by the absence of the ‘nucleus’ and of the ‘ con- 
“ tractile vesicle,’ neither of which organs has yet been detected in 
“ any members of this group.” 
(2.) In the greater tendency to blend of its irregular processes, 
or c pseudcpodia,’ which “ present no approach to definiteness, either 
“ in shape, size, or number. Sometimes they appear cylindrical, and 
“ sometimes form broad, flat bands; whilst they are often drawn into 
“ threads of such extreme tenuity as to require a high microscopic 
“ power for their discernment; they coalesce with each other so 
“ readily and completely, that no part of their substance can be re- 
“ garded as having more than a viscous consistence; their margins are 
* Natural History Review for April and October , 1861 . 
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