ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 337 



Physiological Interpretation of Flower-colour.* — M. Wheldale has 

 tested many colour- varieties of Stocks and Sweet-Peas for oxidases, and 

 finds that all such varieties give strong reaction, either direct or indirect. 

 The results obtained can be explained by the assumption that production 

 of flower-colour is due to the presence of an organic substance of the 

 nature of a peroxide ; when the latter is acted upon by peroxidase, 

 nascent oxygen is produced. This nascent oxygen acts upon the chro- 

 niogen present with the production of an anthocyanic pigment. A 

 ferment is also necessary to reoxidise the original peroxide. 



Inheritance of Sex in Lychnis.f — G. H. Shull has studied the 

 question of sex in Lychnis dioica, and finds that pure-bred families have 

 hermaphrodite mutants, the ratio of mutability being about 1 : 1000. 

 These hermaphrodites were fully functional males and females and were 

 not diseased ; they were of two kinds, some behaving like normal males 

 and others transmitting the hermaphrodite character to the male off- 

 spring. The hermaphrodites appear to be modified males, as shown by 

 the offspring produced when they were used as pollen parents. The 

 results agree with those obtained with Bryonia, showing the homo- 

 zygous character of the females and the heterozygous character of the 

 males. These results prove that Strassburger was incorrect in assuming 

 that hermaphrodites were diseased females. The significance of the sex- 

 ratios is not yet understood, and there appears to be a greater variability 

 in sex-ratios than in colour- ratios. 



Inheritance of Colour in Lychnis. J — G. H. Shull has also studied 

 colour-inheritance in Lychnis dioica, and finds that the purple colour is a 

 compound similar to that found in Lathyrus, etc. Two types of colour 

 prevail, one being more red and the other more blue, the former being 

 an acid colour and the latter alkaline. The blue is hypostatic to the 

 red, this being the reverse of what exists in most other plants. It is at 

 present uncertain whether this condition results from positive acidity or 

 alkalinity, or whether only one colour is positive and the other colour is 

 produced when the positive colour is in the heterozygous state. Crosses 

 of white flowered plants often result in progenies of purple-coloured 

 flowers, or of purple and white in the ratios 1 : 1, 3 : 5, or 1 : 3. 



CRYPTOGAMS. 



Pteridophyta. 

 (By A. Gepp, M.A. F.L.S.) 



Prothallia of Aneimia and Lygodium.§ — E. M. Twiss gives an 

 account of the prothallia of Aneimia and Lyyodium. The spores in 

 each case have three coats ; the extine is formed first, and changes later 

 from cellulose to suberin and pectin. The intine is the second coat 

 formed ; it remains as a delicate cellulose wall. Thirdly, the epispore is 

 formed, arising from the tapetal protoplasm. In the germinating spore 

 the first wall divides the spore contents into two unequal cells, from the 



* Roy. Soc. Rep. Evol. Coram., v. (1909) pp. 26-31. 



t Bot. Gaz., xlis. (1910) pp. 110-25 (2 figs.). 



X Amer. Nat., xliv. (1910) pp. 83-91. 



§ Bot. Gaz., xlix. (1910) pp. 168-S1 (2 pis.). 



June loth, 1910 2 A 



