644 SUMMARY OF CURRENT RESEARCHES RELATING TO 



with 1-3 gram of honey), tho bees must suck 2129 flowers of the 

 alpine rose, 2000 of the acacia (Bobinia viscosa), and 5000 of the 

 sainfoin (Onobrycliis saliva). 



Proteid Substance in Latex.*— The examination of seeds of 

 various plants has shown that certain globulins, albumosc, albu- 

 minates, and coagulated proteids, can be isolated; and Martin has 

 investigated the nature of certain proteids in the dried milk of the 

 fruit of the papaw plant (Carica papaya). Mr. J. E. Green now 

 gives the results of his researches on several caoutchouc-yielding 

 plants, and describes the numerous tests which he applied to the 

 latex, preserved in alcohol. These researches were made on Mimusops 

 globosa, Manihot Glaziovii, Brosimum galactodendron, and others; as 

 well as on lettuce and cabbage plants. He agrees with Martin that 

 no true peptone is present in plants. 



The following are the proteids found to be present : — (1) A dia- 

 lysable proteid, resembling peptone, but which is not converted into 

 true peptone by the action of pepsin. Martin's proteid obtained from 

 the papaw plant gives the biuret reaction, whereas this proteid does 

 not do so. (2) Hemialbumose, found in the lettuce ; this resembles 

 Vines's hemialbumose and Martin's a-phytalbumose. (3) Albumose, 

 in Mimusops. (4) Albumin, in Brosimum. (5) Globulin, in Manihot. 

 Both the two last seem to be the same bodies as described by Martin 

 as occurring in papaw juice. The albumin is probably the same 

 substance as Boussingault's "vegetable fibrin"; till lately no true 

 albumin has been found in plants. 



New Nitrogenous Constituent of Plants, j— Herren E. Schulzo 

 and E. Bosshard have found a new chomical substance in young 

 clover-plants, the cotyledons of cucumber-seedlings, young lupins, 

 probably in the pollen of Pinus sylvestris, and ergot, usually in very 

 minute quantities, in the last case alone amounting to 0*1 per cent. 

 It crystallizes with the composition C lfi H 20 N 8 O 8 , and its discoverers 

 have given it the name vernin. By heating with hydrochloric acid it 

 yields guanin. 



Pith of Dicotyledons.:}: — Herr F. v. Mentovich describes the pith 

 in a large number of dicotyledonous orders, which he classifies under 

 two groups, climbing and non-climbing plants. The following are 

 some of the more important observations : — 



The pith-cells of woody plants may be classed under two physio- 

 logical groups, according as their cell-walls are lignified or remain 

 unchanged. In those cases where all the cells are lignified the change 

 usually commences in the first, less often in the second or in later 

 years. Passive pith results from the cells losing their vitality after 

 becoming lignified ; their walls are then all of the same thickness. 



* Proc. Roy. Soc., xl. (1886) pp. 28-39. 



+ Zeitschr. f. Physiol. Ghemie, x. (1886) pp. 80-9. See Bot. Oentralbl., xxvi. 

 (1886) p. 100. 



X Mentovich, F. von, 'Histology of Pith, with especial reference to Dicoty- 

 ledons' (Magyar), 37 pp. (1 pi.), Kolozsvar, 1885. See Bot. Centralbl., xxvi. 

 (1886) p. 67. 



