ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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involucratm, and in the Marchantiese lobatae and radiatse they show 
but a partially thalline structure. It is also necessary to recognize that 
there are profound differences, both morphologic and physiologic, 
between the lobes and the rays of the capitulum ; these terms were 
applied by Nees ab Esenbeck to MarchaMia polymorpha, and have been 
employed by subsequent authors in a contradictory manner. In the 
female capitula and male discs with channelled peduncles there is an 
arrangement for water-absorption which has never been investigated 
from the point of view of direct or indirect alimentation ; and from 
studying it the author has found proof that (contrary to current ideas) 
all fruit-bearing apparatus and all pedunculate male apparatus is 
effectively constituted of an agglomeration of thalli which proceed from 
diverse ramifications of the same initial thallus. On the strength of all 
these facts, and in the light of other critical observations, the author 
shows that the existing classification of Marchantieae cannot be main- 
tained, relying as it does partly on inexact facts and partly on inconstant 
characters. He therefore proposes a new classification founded on 
other characters more important and less ambiguous — characters which 
by their constancy and simplicity permit almost always the determina- 
tion of groups and genera with the help of a simple lens, if not by the 
unaided eye. The group divisions are as follows : — (I.) Marchantioidese 
non sulcatae include (1) Involucratae nec sulcatae ( Glevea , Lunularia ) ; 
(2) Subinvolucratae (Plagiochasma) . (II.) Marchantioideae sulcatae 
include (3) Inferiores ( Corbierella , Exormotheca , Fegatella ) ; (4) Involu- 
cratae sulcatae ( Sauteria , Peltolepis ) ; (5) Lobatae ( Reboulia , JVeesiella, 
Grimaldia , Fimbriaria , Dumortiera, Bucegia ; (6) Itadiatae (. Preissia , 
Marchantia). A. G. 
Embryogeny and Sporogenesis in Reboulia hemisphaerica. — 
Arthur W. Haupt (Bot. Gaz ., 71, 1921, 446-53, pi. and figs.). A 
continuation of a previous paper (tom. cit ., 61). (1) The embryo of 
Reboulia develops without formation of an octant stage characteristic 
of some other Marchantiaceae. (2) The first transverse wall in the 
fertilized egg separates off the foot-forming cell from that which is to 
form the seta and capsule. Four horizontally super- imposed cells 
usually occur, each new one being cut off from the outermost segment. 
From the lowest of the four arises the foot, from the next the seta, 
from the upper two the capsule. (3) The sporogenous tissue is formed 
relatively early. (4) In the development of spore mother-cells and 
elaters the walls around the sporogenous cells become mucilaginous, 
the protoplasts of the former assume an amoeboid form, and fiually 
become large and spherical, while those of the latter are slender and 
elongated. A new cell wall is laid down around both spore mother- 
cells and elaters. The assumption of an amoeboid form by the young 
mother-cells is a feature related to their nutrition. (6) An elater in 
Reboulia is homologous with a single-spore mother-cell, and not with a 
row of them. (7) The exine and intine are differentiated in the tetrad 
stage, and the epispore has begun to develop. The formation of a 
double spiral band on the elaters is accompanied by a condensation and 
ultimate disappearance of the protoplasm. (8) The short seta and 
bulbous foot are primitive features of the genus. A. G. 
