732 SUMMARY OF CUEEENT BESEAECHES EELATING TO 



outward the fibrils composing them become more sharply defined, 

 elongate, and converge at their apices. The events that follow are 

 essentially the same as those in Iris, Disporum and Hesperaloe. 



The author suggests the following classification : — 



Type 1, represented by Gladiolus, Iris, Dis'ponnn, Hesperaloe, Hedera, 

 Osmanda. 



Type 2, by Cobcea, Passiflora, Lavatera. 



Type 3, by Equisetum. 



Type 4, by Agave. 



Reduction of Chromosomes.* — J. B. Farmer and J. E. S. Moore 

 have re-investigated the disputed question of the method of chromosome 

 reduction in a number of plants and animals. They agree with neither 

 of the two usual interpretations, but believe that after splitting longi- 

 tudinally the spireme thread as a whole becomes bent into distinct loops 

 and U-shaped figures. The original split in the arms of the loops usually 

 disappears, and the two arms become approximated and form the 

 chromosomes, which may afterwards take on the form of rings or rods. 

 The number of chromatic loops corresponds with the reduced number of 

 chromosomes, so that it seems evident that the chromosomes are really 

 bivalent. The chromosome breaks apart during the heterotype division 

 at the bend of the loop, bringing about a reduction which is qualitative 

 as well as quantitative. The actual separation of the longitudinal halves 

 observed in the early spireme is deferred until the second division. 



Crystal-cells and the Leaf of Citrus.f — H. v. Guttenberg has 

 studied the idioblasts containing calcium oxalate in leaves of Citrus 

 medica and C. vulgaris. He finds them to be of subepidermal origin, 

 arising in the uppermost layer of the palisade tissue and the lowest layer 

 of the spongy parenchyma. The crystals are surrounded in an early 

 stage by a cellulose membrane, which later becomes blended with the 

 thickening cell-membrane. The crystal-cells penetrate by sliding growth 

 into the epidermis, thereby splitting the wall of the overlying epidermal 

 cells. In many cases they reach the outer wall and displace the layer of 

 cellulose, replacing it by their own. Finally they exert an influence on 

 the formation of the cuticular layer, in that, instead of a series of 

 larger peg-like outgrowths, an irregular quantity of smaller ones is 

 formed. 



Alkaloids of Dicentra formosa.J — &• Heyl, by digesting roots of 

 this plant with alcohol containing some acetic acid, obtained among 

 other bodies two alkaloids in small quantities which have some re- 

 semblance to homochelidonine and chelidonine respectively, but appear 

 to be different from these. Along with the first a small quantity of a 

 greenish-yellow substance crystallises, which gives a blue fluorescence in 

 alcoholic solution and is perhaps identical with the colouring matter 

 isolated by Schlotterbeck and Watkins from Stylophorum diphyllum. 



* Proc. Roy. Soc., lxxii. (1903) p. 104 (6 figs.). 

 t S.B. k. Akad. Wiss. Wien, cxi. (1902) pp. 855-72 (1 pi.). 

 % Arch. Pharm., ccxli. (1003) pp. 313-20. See also Journ. Chem. Soc. lxxxiv. i. 

 (1003) p. 716. 



