( 400 ) 
fcul've of the binary system formed by D and L, so to speak “thermic" 
analyses of their solutions, which might have been compared with the 
polarimetric ones. It is to be regretted that these investigators have 
not applied this check as now it cannot, provisionally, be decided 
whether their isotherms exhibit the true form or not. From my 
results with the strychnine tartrates, I think I may decide upon the 
latter view. The truth may, however, be revealed by a determination 
of the complete isotherms or, perhaps with sufficient accuracy, by 
melting point determinations of the residues left on evaporation. 
Utrecht. Org. Chem. Lab. of the Univ. 
Botany. — 11 Contribution to the knowledge of water-secretion in plants ”. 
By Dr. W. Burck. 
(Communicated in the meeting of October 30, 1909.) 
II. Secretion of water in the flower. 
After Treub l ) showed in 1890 that the flower-buds of Spathodea 
campanulata Beauv. are filled with a watery fluid, a similar secretion 
of water in closed flower-buds has also been observed in a few 
other tropical plants. 
Lagerheim 2 ) observed the same phenomenon in a South-American 
Solanacea, Jochroma macrocalyx Benth. Gregor Kraus 3 ) soon 
afterwards described the water-calyces of Parmentiera cerifera 
Seem., and Hallter 4 j those of Leea amabilis. Later a detailed 
paper was published by Koorders b ) on the flower-buds of the 
Bignoniaceae: Parmentiera cerifera Seem., Crescentia Cujete Linn., 
Kigelia pinnata DC., Heterophragma adenophyllum, Seem., Stereo- 
spermum hypostictum Miq.; of the Solanaceae: Juanulloa parasitica 
Ruiz et Pav., Nicandra physaloides Gartn.; of the Verbenacea 
Clerodendron Minahassae T. et B. and of a ScrophuJarinea [llysanthes 
spec. A fterwards there followed important contributions by Shibata *) 
x ) Treub; M. Annales du Jardin botanique de Buitenzorg. Vol. VIII. 1890 
2 ) Lagerheim. Zur Biologie der Jochroma macrocalyx Benth. Berichte der 
deutsch. bot. Gesellsch. Bd. 9, Jahrg. 1891. 
3 ) Kraus, G. Wasserhaltige Kelche bei Parmentiera cerifera Seem. Flora Bd. 
81, p. 435-437. 
4 ) Hallier, H. Ueber Leea amabilis und ihre Wasserkelche. Annales du Jardin 
botanique de Buitenzorg. Vol. XIV. 1897. 
5 ) Koorders, S. H.. Ueber die Blutenknospen-Hydathoden einiger tropischen 
Pflanzen. Annales du Jardin botanique de Buitenzorg. Vol. XIV. 1897. 
6 ) Shibata, K. Zur Kenntnis der Kelch- und Knospenhydathoden. Bot. Centralblatt 
1900. Bd. LXXXIII. 
