HARDWICKE'S SCIENCE-GOSSIP. 



117 



himself of the existence of the cilia. I fancy he will 

 experience considerable difficulty in cutting the 

 sections, and perhaps he will learn for himself what I 

 mean by the "capillarity" between the individual 

 cilia and the cell body. These cilia are infinitely 

 smaller and more delicate than those of the human 

 epididymis, or mammalian tracheae ; they resemble 

 those seen on Paramecium bnrsaria or Opalina 

 ra/iarum. It is just this "capillarity," or sticking 

 together, that makes it' so difficult to preserve speci- 

 mens of the infusoria in such a way as to show the 

 cilia.— .P. E. Wallis. 



BOTANY. 



Cephalanthera grandifolia and C. ensi- 

 folia. — In Science-Gossip for April last (p. 91), 

 C. P. in speaking of Cephalanthera grandi flora and 

 C. ensifolia, says that the flower spike of the latter is 

 smaller than that of grand 'flora and has " a few loose 

 flowers." On referring to Bentham's "Illustrations of 

 the British Flora," I find that he gives the flower 

 spike of ensifolia with five flowers only, whilst there 

 are eight shown on the spike of the other species ; so 

 that C. P.'s statements are certainly corroborated by 

 good authority. Under these circumstances, I feel 

 some diffidence in stating that my experience does not 

 accord with that of C. P. and Mr. Bentham. I have 

 been well acquainted with ensifolia for some years, 

 and have seen it growing in Germany, Switzerland, 

 and Italy in at least twenty localities. In particular, 

 in the spring of 1882, I found it on one of the 

 mountains near Varese, in large numbers, and I can 

 state positively that, as a rule, the flower spikes on 

 these plants, as well as on those found in Germany 

 and Switzerland, were for the most part longer and 

 more regular and had more flowers on them than 

 most of the spikes of granditlora that I have ever 

 met with. I confess that I have only seen this last 

 species in two localities, one in a wood just above 

 Weggis, close to the path up the Righi. Here, in 

 1883, I found about a dozen plants, but none of these 

 had more than four or five flowers. The other 

 locality is on the South Downs, where, in 18S4, I 

 found it growing in abundance under beech-trees. 

 The spikes in this latter case were slightly larger, 

 i.e. had more flowers than the Swiss ones, but still 

 they were not so long as average specimens of 

 ensifolia, nor had they as many flowers. I have never 

 seen C. rubra in England, but I found a good 

 many plants of it at Engelberg, two or three years 

 ago. Like grandiflora, it grows in open woods which 

 have but little undergrowth, and evidently prefers 

 shade. Bentham says of ensifolia, " stations the 

 same as those of grandiflora; " but, in point of fact, 

 it is almost always found, not in woods, like grandi- 

 flora, but in open, though bushy places, and I should 

 say prefers a sunny position. At least, that is my 



experience. I have omitted to say that ensifolia 

 is, I think, much more generally distributed than 

 grandiflora, but it is not usually found in such abund- 

 ance where it does occur. — R. B. P., St. Lconards- 

 on-Sea. 



The Wind and the Tree-tops. — Since 1875, 

 the writer has observed in various parts of the 

 country, one hundred and fifty-six observed cases of 

 injury to the trunks or branches of trees by wind. 

 Of all ordinary trees, the .common red maple appears 

 to suffer most \ in hard winds, and the whole one 

 hundred and fifty-six observed cases of injury were 

 confined to the various species of deciduous trees. 

 The writer has seen hundreds of long-leaf pines in 

 Georgia and Florida that had been blown up by the 

 roots, but not one injured in trunk or branch while 

 the tree was yet standing. Also close inquiry in 

 Iowa and a whole summer's observation among the 

 white pines of Tennessee failed to reveal a single case 

 in which a tree of that species was injured by the 

 wind. Of the one hundred and fifty-six observed 

 instances of injury, sixty-one per cent, were limbs split 

 off at the crotch. The crotches of a tree are its weak 

 points. Nature recognises this fact, and guards 

 against the weakness by swelling out the wood about 

 the points of branching. Notably is this true of the 

 white pine. In a large tree of this species, the limbs 

 come out in regular whorls about two feet apart. 

 Midway between each two successive whorls the 

 centre axis of the tree has a minimum size. Above 

 and below this point of least circumference, the trunk 

 gradually swells out to support the successive sets of 

 branches. In sixty per cent, of the observed injuries 

 the trunk divided into two or more large nearly equal 

 branches, and one of these was the injured member. 

 These large limbs swaying in a hard wind act as 

 great levers, and are frequently not sufficiently 

 supported at the crotches. The meaning of all this 

 is that a tree of which the trunk habitually divides 

 into large, nearly equal branches, is much more liable 

 to be injured than one having a strong central axis 

 with many small limbs, as, for example, the white 

 pine. Thus the accumulated effects of the wind have 

 undoubtedly been to develop excurrent forms of tree- 

 top. But the question naturally arises why pines, 

 spruces, &c, have this form in greater perfection than 

 other trees. Well, in the first place, deciduous trees 

 are usually injured by the wind only while in foliage, 

 are practically exposed to the action of the wind for 

 at least twice as great a time each year as are maples, 

 elms, &c. Then, too, according to palaeontology, the 

 cone-bearing evergreens came into existence many 

 thousand, perhaps millions of years before any tree 

 that annually sheds its leaves. Thus the coniferous 

 evergreens have had a vastly longer time in which to 

 accumulate the effects of the wind and develop an 

 excurrent form of top than have deciduous trees. — 

 B. F. Hoyt) in American Naturalist. 



