NOTES. 
SPORANGIA OF LITOSIPHON, HAEV.-A CORRECTION. 
— I regret that I fell into error in stating (Annals of Botany, Vol. VIII, 
p. 459) that the plurilocular sporangia of Lit 0 siphon are unknown. 
Dr. Bornet has called my attention to the following paragraph (which 
I ought to have remembered) in the Etudes Phycologiques of Thuret 
and Bornet, p. 15 : ‘A cote du Punctaria se place le Litosiphon , 
Harv., dont la fructification est tout a fait semblable. Dans les deux 
genres les sporanges uniloculaires sont globuleux, irr^gulihrement 
£pars sur la fronde, a la surface de laquelle ils ne font qu’une Mghre 
saillie. De part et d'autre les sporanges pluriloculaires sont disposes 
en groupes, et r^sultent de la division des cellules de la couche 
corticale. . . Les cellules corticales se divisent simplement, sans que 
leur forme soit modifiee, en quatre ou huit logettes dont chacune 
renferme un gros zoospore.' As the same error is made in Reinke’s 
Atlas deutscher Meeresalgen (II. 3-5, S. 61) its correction is the more 
necessary. 
T. JOHNSON, Dublin. 
EXPERIMENTAL RESEARCHES ON VEGETABLE AS- 
SIMILATION AND RESPIRATION. NO. 1. ON A NEW 
METHOD FOR INVESTIGATING THE CARBONIC ACID 
EXCHANGES OF PLANTS 1 . By F. F. Blackman, B.Sc., De- 
monstrator of Botany in the University of Cambridge. — -All the 
processes hitherto available for the estimation of carbon dioxide in 
its biological relations are open to serious objections, either on the 
score of the amount of time involved in their performance or of their 
inadaptability to the estimation of small quantities of carbon dioxide 
when slowly evolved. 
The present communication describes an apparatus in which, as 
a result of two years' work, I have succeeded in combining a high 
degree of chemical accuracy with special adaptability to biological 
research. 
1 Abstract of a paper read before the Royal Society. 
M 
