Cavers. Notes on Yorkshire Bryophytes. 49 
before the rupture of the exospore or outer coat. The young 
plant at first grows in all directions, so that instead of forming 
a filament (germ-tube), as in most liverworts, it consists of a 
small oval mass of cells. At one end of this mass the super- 
ficial cells grow out to form rhizoids, while one of the cells at 
the other end becomes larger than the others, and divides by 
intersecting walls, forming a three-sided apical cell. The first 
few leaves are simple rows of cells, then come small bilobed 
cell-plates, the lower lobe of the side leaves only becoming 
pitcher-like after about a dozen of these simple leaves have been 
formed. The under leaves are at first represented only by small 
tufts of rhizoids, and when rhizoids occur on the mature plant 
they always grow out from the basal part of an under-leaf. 
Isolated leaves of /. dilatata and F. tamariscz, or even 
small pieces including only a few cells, are capable of giving 
rise to new plants when cultivated. By growing leaves and 
leaf-fragments in culture solutions, the writer has several times 
obtained well grown plants, and can verify for both these species 
the account given for /. dilatata by Schostakowitsch,* who 
showed that the growth proceeds from a single leaf-cell; this 
cell divides so as to form two tiers with four cells in each, and 
the four upper cells then give rise to a small ovoid mass of cells, 
one of which forms the apical cell of the young plant. 
Small disc-like cell masses (gemma) are sometimes formed 
on the leaves of /. dlatata and F. tamarisct by the growth and 
division of a single leaf-cell. These gemmae give rise to new 
plants, as also do the outgrowths on the perianth of /. dlatata 
when cultivated. t 
For kind assistance in the supply of specimens of Hepatice, 
I am indebted to Messrs. W. Ingham, S. M. Macvicar, M. B. 
Slater, G. Stabler, and G. Webster, to whom I take this oppor- 
tunity of expressing my thanks. 
The majority of the illustrations in this paper have been re- 
produced from photomicrographs kindly taken for me by Prof. 
E. L. Watkin, M.A., Hartley University College, Southampton. 
In the investigation of the Hepatica, | have been materially 
assisted by a grant allotted by the Government Grant Committee 
of the Royal Society. 
* ©Flora,’ 1894. 
+ Berggren (/Jakttagelser dfver mossornas kénlosa fortplanting, etc., 
Lund, 1895) says that the pitchers of /. fragzlzfolia, which readily become 
detached from the plant, give rise to leafy shoots on being set free. See the 
writer's paper ‘On a sexual reproduction and regeneration in Hepatice,’ 
‘New Phytologist,’ vol. 2, 1903. 
—) 
1907 February tr. 
