1905] CURRENT LITERATURE 153 
is transferred, the seedling becoming mainly a foot. Vascular elements form 
in the foot, and its central part grows out into the bark. Strands of infecting 
cells grow toward the medullary rays of the host, through these to the cambium, 
and finally effect an attachment with the young xylem elements. While the 
parasite is thus establishing a connection with the young wood, the main part of 
the haustorium forms a mass of parasitic cells in the cortex of the host. From 
this cortical mass buds arise and develop into branches that grow out through 
the bark into the air. The author remarks that “‘we have here an instance of 
regeneration without wounding, amputation, or other pathological stimulus. 
The small part of the seedling which penetrates the host forms and develops 
stem and leaves; a small part of one SS root—develops into a complete 
plant by Snadng the missing members.””—J. M. C 
STEINBRINCK ° finds that Mrz made a very imperfect study of the absorption 
hairs of Tillandsia, and that his erroneous conclusion could have been avoided 
easily by reference to published investigations of the author. According to MEz 
the four central and empty cells of the hair are free from air and collapsed when 
dry; but when the thickened portion of the shield absorbs water the appressed 
walls are forced apart, leaving lumina into which water passes because of negative 
pressure. The author finds that negative pressure is not a factor at all, and bases 
this conclusion upon a study of the mechanics of cohesion involved in the shrink- 
age of artificial cells to which he finds natural cells are comparable. The author 
first demonstrates that water exercises a cohesive power, which being so well 
known is perhaps unnecessary. Next he shows that the shrinkage and collapse 
of artificial cells occurs in a vacuum as well as under ordinary pressure; also that 
the tension present in a membrane through which water is passing to supply 
evaporation is independent of air pressure. In the latter case water placed on 
the surface of such a transpiring membrane is quickly drawn inside because the 
sion pull of the water already inside extends through the fine pores of the 
membrane. Of course the greater the elasticity of the membrane the stronger 
cohesion pull it will support and the greater its capacity for bringing outside 
water within the cell. It is in this relation that the thickened Deckel of the scale 
plays a rdle and not as Mrz found.—Raymonp H. Ponp. 
KRaSNOsSELSKy'° has made a study of the influence of injury on the activity 
of the respiratory enzyme in the onion. In agreement with numerous other 
investigators he finds that injury does increase the respiratory activity of vegetable 
tissues, and points out that Stoxiasa’s failure to confirm this observation was 
due to his not allowing his experiments to run for a sufficient length of am 
and that his belief that the results of other workers were due to bacterial con 
INBRINCK, C., Einfiihrende Versuche zur Cohisionsmechanik von Pflanzen- 
zellen nebst Bemerkungen iiber den Saugmechanismus der wasserabsorbierenden 
Haare von Bromeliaceen. Flora 94:464-477. 1905. 
SSELSKY, T., Bildung der Amungsenzyme in verletzten Pflanzen. Ber. 
*© KRASNO 
Deutsch. Bot. Gesells. 23:142-155. 1905. 
