Structure & Development of Targionia hypophylla. 115 
the two extremes. The centrifugal arrangement of the antheridia 
and the scattered distribution of the ventral scales on the disc-like 
receptacle indicate that the latter represents a condensed branch 
system in which dichotomy occurs rapidly and the several growing- 
points formed are of short-lived activity. 
3. The bivalved involucre develops simultaneously with the 
archegonial group and represents the peripheral region of the 
archegonial surface, but its further growth, the formation of inter¬ 
locking processes on its margin, and its closure until the extrusion 
of the capsule are dependent on the occurrence of fertilisation in 
one or more of the archegonia. 
4. The young sporogonium does not show the octant stage 
usually regarded as characteristic of Marchantiales, but approaches 
the “ Jungermannia type,” a row of cells being formed by successive 
transverse divsions before the first longitudinal divisions occur. 
The spore-mother-cells and the elaters occur in approximately equal 
numbers and are irregularly mingled, but there is invariably a layer 
of elater-forming cells immediately within the single-layered 
capsule-wall and these cells may either remain attached by their 
entire length to the inside of the capsule-wall, or by one end only, 
in the former case making the wall two-layered in places, in the 
latter case forming fixed elaters. 
Goldsmiths’ College, 
New Cross, 
London. 
LITERATURE REFERRED TO. 
1: Barnes, C. R., and Land, W. J. G. “ Bryological papers, I. The origin 
of air chambers.” Bot. Gaz., vol. 44, 1907, pp. 197- 
213. 
2. Campbell, D. H. “ Structure and Development of Mosses and Ferns.” 
London,1905. 
3. Cavers, F. “ Contributions to the Biology of the Hepaticae.” Leeds and 
London,1904. 
4. ,, “ Structure and Development of Fegatella conica." Ann. of Bot., 
Vol. 18, 1903, pp. 87-120. 
5. ,, “The Inter-relationships of the Bryophyta.” New Pliyto- 
logist, Vol. 9. 1910, and Vol. 10, 1911 ; New Phytolo- 
gist Reprint No. 4, 1911. 
6. Deutsch, H. “ A Study of Targionia hypophylla .” Bot. Gaz., Vol. 53, 
1912, pp. 492-503. 
7. Kashyap, S. R. “ Morphological and Biological Notes on New and Little- 
known West Himalayan Liverworts, I.” New Phy- 
tologist, Vol. 13, 1914, pp. 206-226. 
