(3g(5 8. Abstammungslehre. 



fielt! 2 strains have been produced one of which bears its ears 3 feet higher 

 on the stalk than the other. The selection of erect and declining ears has 

 resulted in 2 strains, one of which bears its ears 80° nearer the stalk than 

 the other. Curtis (Orono). 



1487) Cook, 0. F., Mutative reversions in Cotton. 



(Circ. No. 53. Bureau Plant Industry. U. S. Dept. Agr. p. 18. 1910.) 

 The close similarities of the variant forms of many different kinds of 

 cotton is taken to indicate that ancestral characteristics are returning to ex- 

 pression. This is more probable than that the many kinds of cotton »are 

 engaged in the formation of closely parallel series of new species«. In other 

 woods, mutative reversions in cotton are of nother common occurrence and 

 are not confined to Single characters but may bring whole series of more pri- 

 mitive varietal characters into expression. These reversions to not depend 

 upon hybridization but occur in 'pure-bred'. Stocks and may be aroused by 

 new or unfavorable environmental conditions, such diversities some- 

 times appearing when a stock is grown in a new locality. This behavior seems 

 to differ from the experience of several breeders of 'pure lines', the difference 

 perhaps resulting from less rigid selection. 



The variations of the different types of cotton have general similarities 

 and may be arranged in parallel series. The fact that the progeny of muta- 

 tive variations is more uniform, renders them peatly superior to hybrids for 

 breeding purposes, and it is considered possible that useful mutative rever- 

 sions may thus be obtained from later generations of 'dilute hybrid Stocks'. 



Gates (St. Louis). 



1488) Cook, 0. F., Cotton selection on the form by the characters 

 of the stalks, leaves and bolls. 



(Circ. No. (3(3. Bureau of Plant Industry. U. S. Dept. Agr. p. 23. 1910.) 

 The writer emphasize the fact that, owing to the extreme susceptibility 

 of the cotton plant to influences of soil and climate, continued selection 

 in every generation is necessary, to keep a variety uniform. By a study of the 

 vegetative characters of the stalks, leaves and bolls, the undesirable variants, 

 which will produce lint of inferior quality or in lessened quantity, may be 

 removed before the time of flowering and thus, by preventing their crossing, 

 Jessen the chances of their reappearance in the next generation. 



Gates (St. Louis). 



1489) Bailey, I. W. , Anatomical characters in the evolution of 

 Pinus. 



(Amer. Nat. 44,521. p. 284—293. 1910.) 

 Anatomical features are of comparatively great constancy, and hence of 

 value in tracing the evolution of the genera. Cretaceous pines as well as 

 Prepinus, the fossil genus of Jeffrey, are found to have exclusively piciform 

 j)its on the lateral walls of the rays, with an absence of marginal ray - tra- 

 cheids. From this condition the subsequent evolutionary changes give among 

 modern pines the development of ray - tracheids, the disappearance of thick- 

 walled ray cells, the origin of large Compound ray pits by the fusion of small 

 pits having circular borders, and the loos of tangential pitting in the autum- 

 nal tracheids. The hard and soft pines with very large lateral ray pits are 

 considered the most advanced of living pines. Gates (St. Louis). 



1490) Methuen, P. A. (New College Oxford), On acollectionof Fresk- 

 water Crustacea from the Transvaal. 



(Proc. Zool. Soc. 1. p. 148—166. 1910.) 



