1905] CURRENT LITERATURE 317 
WaAsIELEWsKI"? has undertaken by theory and. by his own experimental 
data to dispel what he calls the “‘Mitosendogma” of Hecirr. This so-called 
dogma consists in a discrimination between mitosis and amitosis, in which the 
former is regarded as the only process by which nuclear division can be accom 
plished and the potential qualities retained. According to this view, frag- 
mentation of the nucleus is held without exception to involve loss of regeneration 
capacity. According to the author this dogma ignores the fact that amitosis 
is just as normal for many lower organisms as mitosis is for the higher. Further, 
the idea that the nucleus is the bearer of the hereditary qualities is a theory only, 
though so widely accepted as to be regarded often as a fact. A study of the 
influence of chloral hydrate, especially, on nuclear and cell division leads the 
author to conclude that both may occur amitotically in higher plants. This 
tendency to amitosis apparently dormant may be aroused by stimulants. Degen- 
eration as a consequence of amitosis was not observed, and cells so divided can 
Tesume mitotic divisions without loss of capacity for development. Two modes 
of amitotic nuclear divisions were observed: Diatmese (dissection) and Diaspase 
(distraction). Thus, the latter are regarded as members in a phylogenetic series 
which includes mitosis and from which amitosis does not fundamentally differ. 
In the second section the author goes so far as to state that a given nucleus may 
begin its division mitotically and complete it amitotically. The physiological 
¢quivalence of mitosis and amitosis is advocated. NEMEC’s paper, in which the 
author is believed to have confused amitosis with nuclear fusion, appeared after 
this second section had gone to press. The author promises a paper in which 
this matter will be considered—Raymonp H. Ponp. 
Es RECENT PAPER by Lonco's describes the nutrition of the embryo sac in 
is ol. especially in Cucurbita Pepo. The principal point of interest 
behavior of the pollen tube, which, after discharging the usual function 
— age fecundation, serves as an organ of food absorption. About the 
_ the pollen tube reaches the emb o sac, an enlargement occurs in it a short 
sca from its extremity. After fertilization, slender branch-like outgrowths 
ceed from the enlargement and grow along the nucellus to enter a specialized 
ca the outer integument. This region is composed of cells containing 
the 7a as starch, which is extracted by the haustorial_ prolongations of 
Polen tube. In the meantime the epidermis of the nucellus, or its outermost 
ia — Becomes cuticularized and the cells near the chalaza become suber- 
eg it would seem that the path of the food material is through the 
to the a dle of the outer integument to the nutritive tissue, and from oat 
Temainder ata the haustorial prolongations and the pollen tube. The 
——_*1 0! the paper is occupied (x) with an account of the changes that occur 
I 
Riss a W. von, Theoretische und experimentelle Beitrage 2ur Kennt- 
ee - Jahrb. Wiss. Bot. 38: 377-420; 39:581-606. figs. 10. 1904: 
Annalj “ea ms Bracio, Osservazioni e ricerche sulla nutrizione dell’embrione vegetale. 
Rica 2: 373-396. 1905. 
