n8 



HARDWICKE'S SCIENCE-GOSSIP. 



close them frequently contain many liquid inclusions, 

 which does not necessarily imply any connection 

 between the two, though there may possibly be some 

 connection. Micro-crystals of quartz occur, and have 

 been derived from decomposing silicates. In the 

 discussion which followed, Dr. Sorby said that he 

 was probably the first to study the microscopical 

 structure of the Devonian Limestones of Devonshire, 

 but did so chiefly on account of the valuable evidence 

 they afford in connection with the cause of slaty 

 cleavage. Probably on the whole no group of lime- 

 stones presents a greater range of characters. Not 

 only must their original nature have varied much, but 

 the amount of the changes due to chemical reactions 

 and mechanical squeezing has been very variable and 

 great. He congratulated the author on having done 

 so much to elucidate the structure of such interesting 

 rocks Prof. Bonney expressed his sense of the great 

 interest of the author's observations. Through the 

 generosity of the latter he had had the opportunity of 

 examining some of these residues, and could fully 

 confirm several of the author's conclusions. He 

 thought that the quartz crystals, which had often a 

 nucleus of silicate, must have been developed rather 

 slowly in the rock. He considered that these 

 investigations were of great value as illustrating the 

 history of mineral growth and development. 



NOTES AND QUERIES. 



Butterflies in N. France. — I spent a few days 

 last summer at Compiegne (Dept. Oise). In the 

 forest from June 3rd to June loth I observed A. Selene 

 in great abundance ; P. Dorilis also abundant, but 

 I only took males ; C. Palamon, a few worn 

 specimens ; M. Cinxia a few fresh specimens ; 

 Athalia very abundant and three Aurinia. These 

 Melitfece were very local. In a small reed-covered 

 opening of the forest I took E. Medusa, five 

 specimens, just emerged. On the 6th June Arcania 

 ■was first seen, and three days after was very abundant. 

 On the 8th I took three .J. Carthami in a dry sandy 

 clearing. The weather was very unfavourable ; on 

 the 15th I went to Fontainbleau and remained there 

 four days, and took the following : M. Cinxia and M. 

 Parthenia, in abundance and good condition, Crai&gi, 

 Sinapis, P. Maera, Pahemon, S. sao and serratnlce 

 (or alveus ?), a few of each ; two females of P. 

 Dorilis and a few Euphrosyne, Alsus and Bellargus. 

 The weather was cloudy most of the time. — D. 

 Wright. 



European Butterflies. — I want to spend about 

 a fortnight on the Continent this summer, to collect 

 the above, but I do not wish to go very far ; would 

 one of your readers kindly tell me a good place to 

 stop at, where the forests and mountains are acces- 

 sible, say in the Ardennes or Lower Rhine district. — 

 Z>. Wright. 



LEPIDOPTERA in 1891. — It was a curious fact that 

 although we had so much wet weather last year and 

 the general temperature was so much below the 

 average, lepidoptera did not seem to be in much if 

 any diminished numbers ; they were later in their 



usual time of appearing, that was all. Moths seemed 

 to have been adapting themselves to a sort of aquatic 

 existence, for I saw them, on one occasion at least, 

 flying about apparently unheeding amidst the rain- 

 drops just as a heavy thunderstorm was on the point 

 of leaving off. — Albert H. Waters, B.A., Cambridge. 



Neo-Darwtnism. — Apparently evolution is not 

 a science at all, it is a belief and a matter of common 

 observation. There are no types, but objects have a 

 character. No two trees of the same species are one 

 bit alike. Entomology is evolution depicted, and 

 when Darwin was the popular idol, I had a chance 

 interview with the late Mr. G. R. Waterhouse, a very 

 eminent entomologist. He was quite aware of what 

 was wanting in Darwin's propaganda, for he said 

 suggestively, it is a question of adaptation, that is, 

 of the organism to its environment, a view now 

 claimed for Herbert Spencer. Entomology is like- 

 wise evolution in operation. Last October I found a 

 full-fed caterpillar of the red admiral butterfly at 

 Nantes, in France. Just before the final change the 

 colours of the wings showed through the chrysalis, 

 and revealed that the wings were folded like those of 

 a moth, or, in plain English, that the evolution of 

 the butterfly was in progress. — A. H. Swinton. 



The American Aloe. — Perhaps some one 

 who has had practical experience of the manners 

 and customs of this plant will favour us with some 

 comment upon the note thereupon on page 70. 

 "Chambers' Encyclopaedia" tells us of the agave: 

 " In Mexico these plants usually flower in the seventh 

 and eighth, sometimes even fifth or sixth year, and 

 even in poor soils or exposed situations seldom later 

 than the twelfth year, but in our hothouses not until 

 they have reached a very advanced age (forty to sixty- 

 years) ; whence arises the gardeners' fable of their 

 flowering only once in one hundred years. After 

 flowering, the plant always dies down to the ground, 

 but new plants arise from lateral buds." Doubtless- 

 some of your readers, like myself, look to Science- 

 Gossip for reliable information, and for the explosion 

 and not the perpetuation of popular errors. The 

 rep'ort like a rifle-shot, and the apparently rapid 

 development of blossoms thereupon, seem to require 

 scientific explanation. — W. J. Horn. 



Icicles formed from Exuding Tree-sap. — 

 During the recent frosts a number of trees over- 

 hanging a public foot-path were cut back, and on the 

 6th of March I noticed that the sap which had 

 flowed in consequence had formed icicles of con- 

 siderable size. The largest were from six to nine 

 inches long, but the average length was not more 

 than three or four inches. — F. G. -Ping, Croydon. 



Natural History Specimens by Sample Post. 

 — May I be allowed to correct a wrong impression 

 formed by the Rev. Mr. Horsley, from the ambigu- 

 ously-worded document received by him from the 

 Post Office, on the above subject? A letter referring 

 to the. same matter, which I have just received from 

 the secretary of that department, informs me that 

 "the ordinary limits of weight and size for sample 

 packets are applicable " in this case. These limits 

 are not the same for all places ; for countries in the 

 Postal Union they are as follows : length, eight 

 inches ; width, four inches ; depth, two inches ; and 

 weight, eight ounces ; except in the case of Belgium, 

 Canada, France, Greece, Italy, Japan, Luxemburg, 

 Portugal, Switzerland, the Argentine Republic, and 

 the United States, when all limits are raised by 

 one-half. For non-union countries the limits are the 



