The Biological Problem of To-day

wicklungsgeschichte des Menschen

t Physiology; English e

die Wirkung innerer und ?usserer Kr?fte auf Organbildun

ung im Pflanzenreich,

ologie und Physiologie des

che Mechanik der lebend

chez l'Hydatina senta. Comptes rendus des sé

turzüchtung. Eine Erwiderung

er to Professor Weismann.

'Natürlichen Zuchtwahl.' Biol.

es Arbeiterstandes bei den Ameisen. Bi

ltung and Ver

ith Naegeli-as only relatively stable. In course of time external and internal forces may slowly alter it. On the one hand, the idioplasm of the reproductive cells in the course of generations may slowly alter, while, on the other hand, the idioplasm of cell groups in an organism may ac

cess of regeneration, cells and tissues give rise only to cells and tissues of their own order. For further details see

AND GL

of protozoa, de

s, question of the

ntative of the primitive vertebrate

ore complex chemical bodies b

aracteristic mod

, Loeb's exp

ymorphism

tunicate

anism of a character abnormal in

ymorphism

afting exper

roduction fr

riments on

, skin-gra

k, upon

f a number of ultimate living pieces, the biophores, which are th

tosp

hollow sphere, the walls of which consist of a single layer of cel

of formati

ransfusi

, nisus fo

galls

afting,

xual dimorph

imals which form encrustation

origin

and regener