April 1, 1870.] 



HARDWICKE'S SCIENCE-GO SSI P. 



77 



base of the wings on the upper side being brown or 

 nearly black in V. prorsa, whereas in V. lev ana the 

 same part of the wing is rufous. I ascertained, 

 however, that the one is in reality but a variety of 

 the other, in the following manner. Out of a cer- 

 tain number of chrysalids taken from the same 

 brood of caterpillars in the month of June, some 

 were permitted to develop into the perfect insect 

 at their proper date, viz. in July, while the re- 

 mainder were deposited in a cellar in order to retard 

 their maturation until the following spring. These 

 last produced the rufous variety, while in the former 

 the colour was brown or black. One may conclude 

 from these experiments that the Dark- wing (prorsa) 

 should be accounted the type of the species, and 

 that the Rufous-wing (levana) is simply a variation 

 brought about by the influence of the cold to which 

 the chrysalis was submitted during the winter— a 

 variety in fact become constant by the annual repe- 

 tition of the exciting cause. 



"It is invariably the case that Vanessa levana shows 

 itself only in the spring, that is to say, towards the end 

 of April, and then in small quantities only, and that 

 it does not appear later in the season. And it is 

 equally a fact, that prorsa shows itself for the first 

 time in the month of July, that it appears in much 

 greater numbers than the former, and continues to 

 be found throughout the remainder of the summer. 

 Thus the Black-wing (prorsa) is necessarily pro- 

 duced from eggs deposited by the Rufous-wing 

 (levana), which hatch in June; and the rufous 

 come from eggs deposited by the Black or prorsa, 

 which hatch in August or September, and the larvae 

 of which pass through the winter as chrysalids." 



The author's conclusions are illustrated by a 

 circumstance, which, as he avers elsewhere, is of 

 unvarying occurrence. 



It has reference to a beetle (Cassida tmirrsa) 

 sometimes found in England, and widely distributed 

 over France and Germany. Of this species there 

 are two well-known and well-marked varieties, one 

 green and the other red. Such variations of colour 

 are not unfrequent ; but the point of interest here is, 

 that "the green insect always comes forth in spring, 

 whereas the red does not show itself until the 

 middle of summer. This difference of colour ap- 

 pears to arise from the same cause which affects the 

 two butterflies spoken of above." 

 Havre. W. W. Spicek. 



British Fungi.— Mr. M. C. Cooke will be glad 

 to receive notices of the occurrence of any rare 

 species, not already recorded in " Seemann's Jour- 

 nal," or the " Annals of Natural History," with 

 specimens (as a guarantee of accuracy) wherever 

 possible. They are required for the " Handbook of 

 English Fungi," which is intended to be published 

 towards the close of the present year.— Address to 

 192, Piccadilly, W. 



ABOUT THE ELM-TREE. 



[" AM quite sure the readers of Science-Gossip 

 ■*■ would protest against the points at issue be- 

 tween Mrs. Watney and myself becoming an Elm 

 controversy, and I by no means desire or intend 

 that they shall become one ; but as I " attacked " 

 Mrs. Watney's statements, or rather her knowledge, 

 respecting the fruiting of Ulmns campestris and 

 other matters, and asserted what 1 believed to be a 

 truer history of the facts, and as my own assertions 

 are now called in question in this and other maga- 

 zines, I must crave a page or two of space, lest I 

 may be thought to have " attacked " Mrs. Watney 

 in a too arbitrary manner. 



The reason I wrote about it at all was, that I 

 believed Mrs. Watney had strung together the de- 

 scriptions of a few plants, instead of telling us her 

 real experiences, as her paper stated, and that she 

 had betrayed herself by placing plants together that 

 were not generally found at the same time ; and I 

 thought that a lady with Mrs. Watney's undoubted 

 talents and knowledge of Natural History was 

 quite able to give us a little more of the science 

 and a little less of the gossip. If Mrs. Watney had 

 said at first, what she has now said, that she had 

 not really arranged her flowers together in a real 

 vase, I do not think I should have been so ungal- 

 lant as to have attacked her. But now r , I have no 

 doubt, both Mrs. TVatney and I have, during the 

 last few weeks, been studying the natural history 

 of the Elm a little more closely than we ever did 

 before ; and I dare say we are none the worse bota- 

 nists in consequence. / have been working up the 

 subject a little, and I wish to lay before the readers 

 of Science-Gossip the results of my investigation. 



The number of British species into which the 

 genus Ulmns is and has been divided by botanists 

 varies very greatly. In old times, Evelyn (who wrote 

 his " Sylva " in 1678) says :— " Of this there are four 

 or five sorts, and, from the difference of soil and 

 air, divers spurious." But he most particularly 

 speaks of two sorts, and these he calls "the Vulgar, 

 or Mountain Elm," and the " French Elm." There- 

 fore, in his time, it would seem, that there were 

 recognized two principal species, or, as he would, 

 have called them, " sorts," — a native species and a 

 foreign species ; and this is of some importance, 

 because it, in a certain degree, affects the question 

 of producing perfect seed or not. Dr. Hunter, who 

 edited an edition of Evelyn's " Sylva " in 1776, in 

 his copious notes to that work, enumerates six 

 " kinds " on the authority of Mr. Miller. From the 

 descriptions, these are evidently what we should 

 now call varieties of one or two species. I will not 

 copy his descriptions, which would take up too much 

 space, but will enumerate his names, as the English 

 synonyms are rather peculiar: — 



