17 
geneous, in which are imbedded a few strongly refracting particles. This 
description represents the early stage of the nucleus. At a later period the 
plasm becomes turbid, and in a short time there appear round granules. By 
degrees the whole interior is filled with them— large, distinct particles (ova) 
are then seen at the periphery, and in these a central transparent spot soon 
appears. At this stage the capsule disappears, and the matured granules 
or ova are scattered through the parenchyme of the body, which now con- 
tains but few of the original food and other elements. The nucleus 
is thus broken up and lost. The activity of the animal is now greatly 
diminished, and it appears to exist chiefly for the conservation and further 
development of the new brood. The next stage of their development consists 
in the growth of the ova or cells, which contain now a finely molecular 
plasm with a central clear spot. Soon after a large round vesicle appears by 
the side of the central spot. (This is the first so-called contractile vesicle.) 
The young Amoeba, as its protoplasm increases and its vesicle enlarges, 
begins active movement ; more vesicles appear, and finally a nucleus with 
distinct nucleolus is formed from the clear central mass of the early 
protoplasm. 
The young brood has not been seen in the body of its parent after it 
has reached the ovum condition. The ova probably leave the parent as a 
mass of protoplasm, with central spot. The creature is not, therefore, 
viviparous. Wallich, however, observed in the Amoeba princeps — a water 
species — the viviparous brood escape from the parent. Carter also describes 
the development of a brood from the nucleus of a water Amoeba as com- 
mencing with partition of the nuclear substance, followed by regular 
segmentation. 
Greef describes in one specimen of Amoeba Terricola, two elongated dark 
outlined bodies which contained in their interior thread-like filaments. One 
of these bodies protruded partly from the body of the parent. He 
surmises them to be equivalents of the male organ of Infusoria (nuclear). A 
villous mass adheres to one point of the external surface of the animal. 
Wallich found the same in his water species, and observed that the villi or 
hairs are not stiff, but move like the pseudopodia of Khizopods. He regards 
them as prehensile organs. Carter noticed the same appearance, but con- 
siders it inconstant, and not affording any ground for constituting a new 
species as Wallich does. (Am. Villosa?) Greef found the position of this 
villous appendage to be not always at the same end of the body, but attached 
indifferently to any part of the body. The villi of the land Amoebae are not 
so extended as those of the water species, but stiff and short. He agrees 
with Carter in not considering this appendage to be a specific character,— 
