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CURRENT LITERATURE 



MINOR NOTICES 



Mechanics of cell division.— In a study of the mechanics of cell division, 

 GiESENHAGEN' presents the following conclusions. The nucleus, even in the 

 resting condition, has a definite polarity, so that it can divide only in a predeter- 

 mined direction. The median plane in which the cell plate will appear at mitosis 

 is the equatorial plane, and the axis is perpendicular to its center. The axis of the 



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being that of the axis of the mother cell, or a position at right angles to the axis 

 of the mother cell. If the nuclei maintain their positions without any movement, 

 there will be a succession of anticlines and periclines, but many causes may change 

 the position of the nucleus and affect the direction of its axis and consequently 



formed 



The numerous 



variations from the periclinal and anticlinal divisions are disci 

 tions are made as to their causes. — Charles J. Chamberlain 



American Breeders' Association.— The proceedings of the meeting held at 

 Lincoln, Nebraska, January 17-19, 1906, have just been published as the second 

 volume issued by the Association. Naturally the papers var}^ widely in subject 

 and in value, and it is impossible to estimate them by reading. It is clear, how- 

 ever, that fundamental biological problems are being considered; and that views 

 and data are being recorded that are extremely suggestive. Among the strictly 

 botanical topics may be noted the following: Tobacco breeding, The corn plant as 

 affected by date of planting, Some correlated characters in wheat and their trans- 

 mission, Plant adaptation, A method of breeding a strain of alfalfa from a single 

 individual, Correlation of characters in plant breeding. Variation in wheat hybrids, 

 Breeding drought-resistant crops, Fundamental requirements for grain breeding, 



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J. M. C. 



The Dillenian Herbaria,— The herbarium of the University of Oxford 

 contains some collections of great historical interest, among which those of Dil- 

 LENius (1684-1747), the first *'Sherardian" professor of botany, are conspicuous. 

 An account of the Dillenian herbaria has just been published, together with a 

 biographical sketch, selections from correspondence, etc., by Druce,^ edited and 

 with an introduction by Vines, the present *'Sherardian" professor. The collec- 



' GiESENHAGEN, K., Studien uber die Zellteilung im Pflanzenreiche, ein Beitrag 

 zur Entwickelungsmechanik vegetabilischer Gewebe. 8vo. pp. 91. Stuttgart: Fr. 

 Grub. 1905. 



= Druce, G. Claridge, and S. H. Vines, The Dillenian herbaria, pp. cxii+258. 

 Oxford: The Clarendon Press. 1907. 12 sh, 



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