464 Recent Literature. [June, 
lated to call attention to the successive steps in the differentiation 
in the Protozoa of a “ mouth” or ingestive area. 
The author’s system does not recognize the Monera of Haeckel, 
and he rather dogmatically relegates them to the Rhizopods, not 
awaiting further discoveries as to the presence or absence of a nu- 
cleus, dismissing them with the remark that since the Foraminifera, 
included by Haeckel in the group Monera, have been proved to 
possess a nucleus, “A similar demonstration of the possession of 
nucleolar structures in the few remaining organisms relegated to 
this group will not improbably result from their further careful ex- 
amination, with the assistance of the special treatment resorted to 
in the case of the Foraminifera. Finally, it is altogether ques- 
tionable whether the presence or absence of a nucleus or endo- 
plast can be accepted as furnishing a distinct and reliable charac- 
ter even for specific diagnosis. This structure, as,shown at greater 
length in the chapter devoted to the organization of the Infusoria, 
is evidently in many instances an accompaniment only of the ma- 
tured and reproductive phase.” 
r. Kent also, and here we think with excellent reason, dismisses 
as “entirely unnecessary and untenable,” the Profista, a kingdom 
set up by Haeckel and including all organisms supposed to be 
intermediate between the plants and animals and comprising the 
lowest representatives of both; although our author is clearly 
alive to “ the difficulty of indicating a clear line of demarkation 
that shall arbitrarily separate certain unicellular cryptogamic 
plants or Protophyta from the unicellular animals or Protozoa. 
Mr. Kent claims, however, as the result of close investigation on 
his part upon Volvox and Protococcus and certain allies of these 
forms, that he failed to find any periodically contracting vesicles, 
and he thinks that the absence of a contractile vesicle is charac 
recently and independently eliminated by L. Cienkowski and Dr. 
A. de Bary, concerning the structure and life-history of this most 
remarkable group, establishes, however, beyond question Bit” 
purely animal nature. The Mycetozoa, in common with all ordl- 
nary representatives of the Protozoa, originate from minute 
sporaloid bodies which escape from the spore case as monadiform 
animalcules having a soft, plastic body-substance, a single term 
nal flagellum, contractile vesicle and endoplast or nucleus, being 
thus in no way distinguishable from the typical representatives 
the ordinary Flagellata-Pantostomata, as met with in the ae) 
Monas.” He then farther recapitulates their later developme? 
stages, and gives good reasons for their Protozoan nature. 
Another singular and doubtful group, the Labyrinthulida, are 
likewise referred by Mr. Kent, to a position in the Protozoa ™ y 
between the Foraminifera and the Myxomycetes. The sp? 
