8. Abstammungslehre. 617 



1711) Cook, 0. F. and E. M. Meade, Arrangement of parts in tlie 

 cotton plant. 



(Bull. 222, U. S. Dept. Agr. p. 26, figs. 9. 1911.) 



In examining the leaf arrangernent it was found that the New World 

 cottons had their leaves arrange,d in three-eighths spirals, while the Asiatic 

 varieties have a one-third arrangernent when first introduced. Later this may 

 become two-fifths or three-eighths, apparently througb hybridization. Other 

 arrangements studied are those of the branches on the main stem, the leaves 

 and flowers on the fruiting branches, the involucral bracts of the flowers, the 

 lobes of the calyx, the hairs on the seed coat, etc. Gates (London). 



1712) Cook, 0. F., Relation of drought to weevil resistance in 

 Cotton. 



(Bull. 220, U. S. Dept. Agr. p. 30. 1911.) 



The boll weevil, which parasitizes the buds of the cotton plant, adds 

 complication to the problem of adjusting cotton varieties to conditions of cli- 

 raate and soil. In dry regions the dryness not only restricts the growth of 

 the cotton plants but also prevents the propagation of the weevils, while in 

 a w T et season the growth of the plant may be impeded while the development 

 of the weevils is unrestricted. 



This difficulty may be in part overcome in humid regions by the develop- 

 ment of quick-fruiting varieties. The early planting of varieties which fruit 

 early will help to avoid weevil injuries, but this is limited by the fact that 

 too early planting delays development. The weevils feed only on the pollen 

 of the cotton plant, so that the ideal to be sought is the quiekest development 

 from flowering to fruiting. Planting the crop simultaneously and also with 

 the same variety in one locality is also an important measure in minimizing 

 the amount of damage by the weevil. Gates (London). 



1713) Blakeslee, A. F. and C. D. Jarvis, New England Trees in 

 winter. 



(Storrs Agric. Expt. Station Bull. 69. p. 307—576. platea 109. 1911.) 



This excellent manual showing the winter conditions of New England 

 trees is an interesting and useful contribution to tree morphology. Analytical 

 keys to all the genera and species are given, the characters used being chiefly 

 the twigs with their scaly buds and leaf-scars, and the bark. The keys are 

 followed by page descriptions of each species, including habit, bark, twigs, 

 leaf-scars, buds, fruit, distribution, etc., cachaccompanied by apageof photographs 

 showing in each case the winter habit, the trunk and bark characters, fruits, 

 and twigs. The illustrations are notably uniform and excellent, and the whole 

 forms a valuable contribution to the biology of trees in a temperate climate. 

 A glossary and index complete the volume. Gates (London). 



1714) Luoosch, W. (Jena), Was lehrt die Phylogenese der Gelenke 

 für die Beurteilung des Kaugelenkes der Säugetiere? 



(Biolog. Zentralbl. 31,23. p. 73S-751. 1911.) 

 Der Verf. teilt Ergebnisse früherer (1910) und neuer histologischer Ge- 

 lenkuntersuchungen, speziell des Squamosodentalgelenkes einer großen Anzahl 

 von Säugern mit. Das Squamosodentalgelenk besitzt keinen Discus articularis 

 bei Monotremen und Edentaten; bei diesen liegt auf den knorpeligen Gelenk- 

 flächen eine dicke Schicht von Faserknorpel. In die faserige Überkleidung 

 des Unterkiefercondylus strahlen sehnige Züge ein, die der Sehne des Muse, 

 pterygoideus externus entstammen (stark ausgebildet bei Echidna, Tolypeutes, 



