78 BOTANICAL GAZETTE [JANUARY 
water through the stems of submerged aquatics. To call such a stream “the 
transpiration current” is manifestly absurd, unless one changes the meaning 
of the word transpiration. It will be remembered that others have found evidence 
of like movements, so that these new experiments only add somewhat clearer 
evidence as to its existence, which the most elementary consideration of the physi- 
cal conditions would lead one to expect. Yet these authors naively say: ‘‘Prob- 
ably external conditions also affect the results; this point we hope to investigate 
later.” This really is the fundamental point: does not the heating of the leaves 
create the conditions for the circulation of water as truly in this case as in a house 
heating system ?—C. R. B. 
Fixation of free nitrogen.—Portacci reports in a preliminary note’? that 
in a large number of experiments he has demonstrated the fixation of free nitrogen 
in such plants as lichen, salvinia, azolla, fern prothallia, and duckweed. The 
increase of total N in a few cases cited amounts to 33-67 per cent. The full 
paper will be awaited with interest. Potzaccr has a heavy weight of adverse 
evidence to counterbalance. He indicates that the contradictory results of the 
earlier observers, e. g., BoUSSINGAULT and VILLE, were probably due to differences 
in the capacity of different plants for this fixation. It is to be remembered, 
however, that all the recent evidence under improved chemical methods is adverse 
to the idea that ordinary plants are able to utilize N..—C. R. B. 
Prothallium and embryo of Danaea.—CampBeLt?? has made a preliminary 
investigation of the prothallium and embryo in several species of Danaea secured 
in Jamaica. The archegonia are remarkable for the imperfect development of 
the ventral canal cell, which in many cases could not be demonstrated at all. 
The fertilized egg becomes elongated in the direction of the axis of the archego- 
nium before the first division. The hypobasal cell does not divide or there 1s 4 
single division, resulting in a short suspensor, all of the regions of the embryo 
arising from the epibasal cell. This cell gives rise to somewhat irregular quad- 
rants, the two lower ones forming the foot, and the two upper giving rise to stem 
tip and leaf, and later to the root.—J. M. C. 
Chromosomes of Hyacinthus.—Miss Hype" finds that in Hyacinthus in the 
prophase of the heterotypic mitosis the spirem twists into 8 loops which become 
8 chromosomes. The loops break apart at the center so as to form 8 bivalent — 
chromosomes. When fully formed, the chromosomes show a striking difference 
in size, 4 being comparatively large, 3 small, and the remaining one intermediate. 
39 Potiacct, G., Ricerche sull’ assimilazione dell’ azoto atmosferico nei vegetali. 
Atti Ist. Bot. Univ. Pavia II. 13:351-354. 1909. 
40 CaMpBELL, D. H., The prothallium and embryo of Danaea. Preliminary ne: 
Annals of Botany 23:691. 1909 : 
Epirus, The reduction division in the anthers of Hyacinthus orientalis 
4t HYDE, 
Ohio Naturalist 9: 539-544. pl. 32. 1909. 
