238 Blackman and Tans ley. 
( 10 ) Professor Karl Pearson. “On the fundamental conceptions 
of biology.” Biometrika, Vol 1, April, 1902. 
[A reply to Mr. Bateson’s ( 12 )]. 
( 11 ) Professor Karl Pearson. “On the influence of natural 
selection on the variability and correlation of 
organs.” Phil. Trans. (A). Vol. 200, 1902. 
( 12 ) W. Bateson, F.R.S. “Heredity, differentiation, and other 
conceptions of biology.” Proc. Roy. Soc., Vol. 
69, 1901. 
( 13 ) E. Warren, D.Sc. “An observation on inheritance in 
parthenogenesis.” Proc. Roy. Soc., Vol. 65, 1899. 
( 14 ) E. Warren, D.Sc. “Variation and inheritance in the Partheno- 
genetic generations of the Aphis Hyalopterus 
Trirhodus (Walker). Biometrika, Vol. 1, October, 
1901. 
( 15 ) Professor W. F. R.Weldon, F.R.S. “ On Mendel’s Laws of 
alternative inheritance in peas.” Biometrika 
Vol. 1, Jan., 1902. 
A REVISION OF THE CLASSIFICATION OF 
THE GREEN ALG/E 
BV 
F. F. Blackman, 
University Lecturer in Botany, Cambridge. 
AND 
A. G. Tansley, 
Assistant Professor of Botany , University College , London . 
(concluded from page 220.) 
Fam. III. Botrydiaceae. 
Plant-body a well-developed coenocyte, differentiated to form 
“ root ” and “ shoot Chromatophores very numerous. Gametes not 
observed. 
Genus. 
Botrydium. Wallroth, 1815 . 
Plant a pyriform bladder of some size, growing on wet 
clay in which the tubular branched rcot-system 
ramifies. Pyrenoid-like bodies present in the very 
young stages, but they do not form starch. Repro¬ 
duction by division of the contents to form numerous 
zoospores with two chromatophores and presumably 
two unequal flagella, and also by oval aplancspores 
which may develop to form new individuals or 
zoosporangia. 
