INFUSORIA, RHIZOPODA. 
Prot, 5 
longer and thinner, often with a larger number of ectodermal cells, 
a different shape of the head, &c., producing vermiform embryos, 
which, simply increasing in size, are developed into typical DicyemidcB ; 
and “ rhombogenous ” Dicyemidce, producing “ infusoriform ” embryos 
of a rather complicated structure. The further metamorphoses of 
the infusoroid embryos are unknown ; they are probably destined to 
ensure the preservation of the species by dissemination, while the 
filiform embryos are developed to maturity in the individual host 
of their parent. The germs of the filiform embryos originate endo- 
geneously in the delicate protoplasmic filaments traversing the cavity 
of the axial cell ; the two first formed are constantly found at an 
early period in the embryo, and they are often present before its 
birth in great number, and already partially transformed into em- 
bryos. The germs do not multiply by fission, and are developed 
through segmentation ; of the first formed four cells, one constitutes the 
endodermal cell, which is by and by covered by the others during their 
continued growth and multiplication, until the number of ectodermal 
cells typical to the species is reached. The ciliated embryos are set free 
through the “oral pole” of the head (corresponding to the closed up 
“blastopore”), or by pushing their way between or through the ecto- 
dermal cells of the body. The “ rhombogenous ” specimens contain in 
the interior of their axial coll a small number of peculiar cells (“ germi- 
genes”), in which are successively developed endogeneously a large 
number of daughter cells, which, after their separation from the mother 
cell, constitute the germs, and are, through regular segmentation, developed 
into the “ infusoriform ” embryos, which are set free in the same manner 
as the filiform, but are capable of living for some time in sea-water, 
while this medium becomes immediately fatal to the adult Dicyemidm 
and to the filiform embryos. 
RHIZOPODA. 
1. Archer, W. Rdsumci of recent contributions to our knowledge of 
freshwater Rhizopoda. Pt. i. Heliozoa. Q. J. Micr. Sci. (2) xvi. 
pp. 283-309, 347-376, pis. xxi. & xxii. 
2. Barnard, W. S. Protozoan Studies. P. Am. Ass. xxiv. pp. 
240-242. 
3. Blake, J. F. ‘ On Renulina sorhyana, M. Micr. J. xv. pp. 262-264. 
4. Brady, H. S. On some Foraminifera from the Loo Choo Islands. 
P. R. Irish Ac. (2) ii. pp. 589 & 590 ; Q. J. Micr. Sci. (2) xvi. 
pp. 404-406. 
5. Broeck, E. V. D. Etude sur les Foraminiferes de la Barbade, 
receuillis par L. Agassiz, precede de quelques considerations sur 
la classification et la nomenclature des Foraminiferes. Ann. 
Soc. Belg. Micr. ii. p. 55 et seq. pis. ii. & iii. (abstr. J. Zool. v. pp. 
378-381). 
187(3, [voL. XIII.] J 5 
