216 Miscellaneous. 



manency in proportion to tbcir induracy is also another strong point. 

 Tiie soft ones of the iStrohus section retain vitality little longer than 

 some true leaves, while the spinescent ones of P: austriaca remain 

 green for four or five years. But the strongest of all points is, that 

 on dissection of an old fascicle, it will be found to have a distinct 

 connexion wdth the woody system of the tree, and that these minute 

 woody axilla) under each fascicle increase in size with the age of the 

 sheath. With a very little encouragement these woody axilla can 

 be induced to elongate and become real branchlets. If the leading 

 shoot, for instance, of a pine be tipped in May just after pushing, 

 bulblets wdll form in every fascicle below, and the next season the 

 bulblets will produce weak branchlets, although this might be said 

 of true leaves, which are supposed to bear an embryo shoot in the 

 axil of every one. So much stress need not be put on this fact, as 

 the others are sufficient ; it is introduced, and its weak nature com- 

 mented on, as it furnishes the chief point in Dr. Dickson's argument 

 for Sciadopitys, which amounts to little more than that the appa- 

 rently single phjdlon is really a double one — a two -leaved fascicle 

 united by a transformed sheath through its whole length. Carriere 

 has since pushed Dr. Dickson's observations further by noting, in the 

 ' Kevue Horticole,' really bifid leaves, with little verticils in the axils 

 (see reference in ' Gardeners' Chronicle,' May 2, 1868) — an observa- 

 tion which I confirm by a specimen exhibited herewith ; yet, as I 

 have said, it is by itself not wholly free from the objection that it 

 may be but a modified form of regular bud-growth ; but, together 

 ■with my other observations, I think they do serve to confirm the 

 point of these so-called leaves being but phyllodea. 



In conclusion, I wiU restate the main points of this paper : — 



The true leaves of Coniferae are usually adnate with the branches. 



Adnation is in proportion to vigour in the genus, species, or in the 

 individuals of the same species or branches of the same individual. 



Many so-called distinct species of Conifera) are the same, but in 

 various states of adnation. — From the forthcoming volume of the Pro- 

 ceedings of the American Association for the Advancement of Science. 

 (Communicated by the Author.) 



Mechanical Reproduction of the Flight of Insects. 

 By M. Makey. 



The author has already shown that by gilding the tips of the 

 fore wings of a hymonopterous insect and allowing it to fiy in the 

 sun, the point of each wing is found to describe a figure of 8, indi- 

 cating that in the course of one elevation and descent the wing 

 moves twice forward and twice baclnvard. To ascertain how this 

 movement is produced, the author took a small glass rod blackened 

 with smoke, and by presenting it to the wdng in ditt\>rent parts of its 

 passage, he found tliat the soot was rubbed sometimes on tlie upper 

 and sometimes on the lower surface, according as the rod was held 

 below or above the course of the wing forwards or backwards. From 



