NOTES AND ABSTRACTS. 



303 



have a favourite tree from which every violent storm wrenches a limb or 

 a branch. A good deal may be done in the early training of a tree so to 

 control its building up that it may best withstand the violence of gales ; 

 and the most important matter in this connection is the development of 

 a strong erect trunk — a central axis of such height and strength and 

 bulk as to be capable of supporting its head of branches easily. It is 

 advisable, therefore, always to prevent the premature forking of the 

 trunk in important trees. In other words, the leading shoot should 

 always be watched, and, by the repression of any rival leaders that may 

 appear, allowed to retain its predominance. This is by no means so 

 troublesome a matter as might appear, for when once a strong leading 

 shoot has been developed it usually keeps its place till the tree begins to 

 assume the shape natural to it. — E. T. C. 



Tulip Disease, The. By A. D. H. (Gard. Chron. No. 845, p. 145 ; 

 March 7, 1903). — The well-known disease of Tulips commonly known 

 as the ' Tulip disease ' is well described in this article : its effects had 

 been known for many years, but the cause has only comparatively 

 recently been found out. The fungus known as Botrytis, or Sclerotinia 

 parasitica, has been described by various authors in this country. The 

 writer of this article appears to be under the impression that Dr. Ritzema 

 Bos, the well-known zoologist, was the first to thoroughly investigate this 

 disease, the result of which investigations he has published in the current 

 number of the " Centralblatt fur Bacteriologie " ; but a very good account of 

 this disease, by Mr. Massee, had already been published in the Journal, 

 R.H.S. xxvi. 1901, p. 43. — G. S. S. 



Tulips, New. Tulipa Micheliana and T. Wilsoniana. By Ed. Andree 

 (Rev. Hort. May 1, 1903, pp. 206, 207 ; coloured plate). — Description of 

 two new introductions from Persia by M. Van Tubergen, Haarlem. T. 

 Micheliana is brilliant scarlet, foliage striped with brown until maturity, 

 base of petals a black lanceolate patch, bordered with yellow. T. Wilsoniana 

 scarlet, leaves undulate, with narrow brown margin. Both very handsome. 



C. T. D. 



Upland Plant Societies, Distribution of, in Kent County, 

 Michigan. By B. E. Livingston (Bot. Gaz. xxxv. No. 1, p. 36 ; with 

 map). — The author commences by describing the climatology and geology 

 of the county, this being mainly glacial drift, with three well-marked 

 terminal moraines. There are five Plant Societies, termed : (1) The 

 Beech-Maple; (2) Maple-Elm- Agrimony ; (3) Oak- Hickory ; (4) Oak- 

 Hazel ; (5) Oak-Pine- Sassafras. Each of these societies is considered 

 with their accompanying plants. Generalising on the upland flora, this 

 is based primarily upon the nature of the superficial soil, and it appears 

 that the most important soil factor is the relative ability of the superficial 

 layers to retain water ; i.e. the controlling soil condition is one of 

 drainage. 



The author then discusses a hypothetical origin of the societies as the 

 glacial period ceased and vegetation followed the retreating glaciers north- 

 wards ; thus he thinks the Pine-Heath group, which to-day reaches farthest 

 north, reached well toward the glacier forest during the ice age. After 



