82 
THE PLANT WORLD. 
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6. Region of cultivation. 
It is recommended that -one type of vegetation be made the 
subject of special study, and the facts of distribution plotted on 
government contour maps. Thus, “ The pupils are trained in the 
use of ordnance maps—itself a most valuable discipline. . . . The 
use of a pocket compass, and perhaps also 1 of a pocket aneroid 
is also seen. The value of contour lines, of scales, and of map 
symbols is realized. The relation between the vegetation and the 
landscape ... is made clear by the personal observations of the 
pupils; and the formation of accurate concepts of the vegetation 
and the landscapes of foreign countries. The regions of the 
locality and of Greenland have been recognized by the pupils, the 
teacher is in the possession of a powerful means of enabling his 
pupils to grasp the significance of the vegetation regions of the 
world.” 
The appeal to enlightened teachers in English schools to put this 
method to the test may also be strongly made to teachers in our 
own country. C. S. G. 
The use of the expression plant “ formation,” in the note above, suggests 
again what a poor term this is. Attention has already been called to this 
fact by Knowlton. (Science II, 19:467. 1904.) The term has been for so 
long a time applied in an entirely different sense that it should be wholly 
dropped as a synonym for plant “association.” C. S. G. 
Winter Shoots of a Species of Chicicweed.— The resting 
buds of water plants known as “ hibernaculae ” are well known 
to every one who has collected any of these plants in the late 
autumn. The term hibernaculum is applied to a winter bud of a 
submerged water plant, one which arises from the shortening, or 
rather the failure to lengthen of the internodes at the end of a 
shoot. This causes the crowding of the leaves into a dense round 
or oval green mass. Hibernacula are very noticeable in such forms 
as have an otherwise loose habit of growth, such as occur in 
species of Utricularia. What appears to be an analogous con¬ 
dition in a land plant, Stellaria nemoritm, a native of Europe, has 
been described.* 
This plant grows on the damp, mossy rocks of the narrow 
*Neger, F. W. Flora, 93 : 160. 6 Feb., 1904. 
