NOTES AND MEMOEANDA. 187 



of these cells begins and continues, in the first case, in one plane, in 

 the second radially. Usually several macrospores come to rest 

 together, and then the young tballi formed from them fuse together 

 into a single irregular mass. The formation of microzoospores was also 

 observed, and their conjugation ; the resulting zygospore grew to the 

 size of a macrospore, and then divided in the same way as the latter. 



Nostoc-colonies in Anthocerotese. — The colonies of parasitic Nostoc 

 occurring in the thallus of various species of Anthoceroteoe were in- 

 vestigated some years siuce by Janczewski, and have now been studied 

 again by Leitgeb. * He finds that the motile filaments of the 

 parasites penetrate through the young stomata, the air-cavities in con- 

 nection with them being then filled with mucilage. Sometimes, how- 

 ever, infection seems to be brought about by a few isolated Nostoc-ceWs, 

 or even by a single cell. It is j^robable that there is more than one 

 species of Nostoc inhabiting the different genera of Anthocerotete, but 

 this is not certain. 



For further details we must refer our readers to the paper itself. 

 It is illustrated by one plate, showing the formation of the stomata 

 and air-cavities, and the relation of the ^os/oc-colonies to them. 



Support for the Head in Drawing with the Camera Lucida. — A 



writer in ' Science-Gossip' t points out the assistance which the 

 draughtsman will receive by keeping the head steady as well as the 

 hand, and explains a device he has made use of for tlais pixrpose. It 

 consists simply of two upright brass rods with a flat sliding cross- 

 bar (covered with some soft subst mce) between them, which can be 

 screwed tight at any height, and on which the forehead is placed in 

 the position desired. 



Alcoholic Fermentation. — The ' Comptes Eendus ' have continued 

 to contain further " observations " and " replies " on the discussion 

 raised between M. Pasteur and M. Berthelot in regard to the i>osthu- 

 mous MSS. of the late Claude Bernard. We noticed at p. 270 of 

 vol. i. the commencement of the controversy, and at p. 82 of this 

 volume M. Pasteur's refutation of M. Bernard's views. This was 

 criticised by M. Berthelot, J who maintained his original view, that 

 the action of ferments is reducible to purely chemical conditions 

 independent of life ; to whom M. Pasteur again replied, § charging 

 M. Berthelot with putting forward entirely gratuitous hypotheses 

 which have never been supported by any personal observations. He 

 thus describes the hypotheses : — 1st. In alcoholic fermentation there 

 is perhaps produced a soluble alcoholic ferment. 2nd. This soluble 

 ferment perhaps consumes itself in proportion to its production. 

 3rd. There are perhaps conditions in which this hypothetical ferment 

 would be produced in greater proportion than the amount destroyed. 

 M. Pasteur deals seriatim with M. Berthelot's objections, and says 

 that if he will endeavour to support his hypotheses by experiments, 



* 'Sitzungsb. k. Wiener Akad. dii Wiss.,' vol. Ixxvii. (187S) p. 411. 

 t 'Hardwicke's Science-Gossip,' No. 170 (1879) p. 32. 

 X ' Comptes Rcndus,' vol. Ixxxvii. (1878) p. 949. 

 § Ibid., p. 1053. 



