52 SELECTED NOTES FROM 



Sugar-Cane. — There are one or two points in Mr. West's des- 

 cription of the sugar-cane, upon which if I express a doubt, that 

 doubt probably arises more from my own ignorance of the subject 

 than from any inaccuracy on his part. On page 7 of an element- 

 ary treatise by Edward Smith, forming part of Orr's Circle of the 

 Sciences, there occurs a description of the tissue called " sclero- 

 gen," accompanied by a figure illustrating its presence in the pith 

 of the elder, from which, and indeed from the appearance of the 

 slide under examination, I should infer that the markings seen on 

 the cell-walls were rather the result of sclerogenous deposit than, 

 as Mr. West observes, in the explanation to his plate (page 48 

 and Plate IV.), indicative of the presence of pores. Again, I 

 have been hitherto under the impression that there was no such 

 thing as a cambium layer in endogenous stems, at least in the 

 situation where it is found in exogens, between the bark and the 

 wood. Smith, at p. 87, says that the bark of endogens "cannot, 

 in any normal instances, be readily separated from the stem, as 

 may be readily seen by attempting to peel a cane. It does not 

 naturally crack, as does the bark of our forest-trees, but is hard, 

 dense, smooth, (usually) non-corrugated, unelastic, but slighdy 

 extensible, and is a permanent, unchanging structure " ; and 

 again, on p. 88, he says : — " It is the fashion to state that endo- 

 gens have no bark, since 7i07ie is separable from the wood, and that 

 the cuticle is simply the hardened, exposed cells of the stem, 

 with the ends of bundles of woody fibres intermixed." All this 

 seems to me incompatible with the thick zone of bark represented 

 by Mr. West's plate ; still less do I understand the existence of an 

 outer zone of growth, or cambium, in plants, which, as their name 

 implies, increase from within — that is, by the passing down of new 

 bundles of woody fibres from the leaves through the cellular 

 matrix of the stem. A. Hammond. 



Eggs of Bot-Fly (pp. 49 and 51). — May I suggest that the circu- 

 lar marks on this object, about which some discussion appears to 

 have arisen, may be the micropyle, whereby the spermatic fila- 

 ments gain access to the yolk. Notices of this micropyle appear 

 in an article by Jabez Hogg on insect eggs in the Intellectual 

 Observer for December, 1867; it is also mentioned in Lowne's 

 "Anatomy of the Blow-Fly," pp. 114, 115. The wavy lines or 

 ridges noticed by Mr. West I take to be indicative of a cellular 

 structure in the chorion or eggshell. Such structure may be 

 noticed in more insect-eggs, and is mentioned by both Hogg and 

 Lowne. I have myself found it to assume a very curious form in 

 the eggs of the great green grasshopper, Acrida viridissivia^ In 

 this egg there is a strong chitinous covering surrounding the yolk, 

 upon which, as upon a basement, an external layer of dumb-bell- 



