Jan. 1, 1S66.] 



SCIENCE-GOSSIP, 



19 



'acaena,' alludes to the prickly nature of the fruit ; 

 the specific, to the resemblance which this plant un- 

 doubtedly shows to the British Burnets (Sanquisorba 

 and P ofc ri/i i,i). Like its European prototypes, this 

 acaena seems not to possess any really important 

 useful properties, otherwise they are as yet not as- 

 certained. The prickly fruits readily adhere to 

 wearing apparel, fleeces, &c, and are thus easily 

 carried about. To destroy a perennial plant like 

 this where it abounds, I see no other means than 

 ploughing it in." — Fcrd. Midler. 



Cocode Mer — (S. G. Vol. I, p. 270.) A doubt is 

 expressed whether the stem of the Lodoicea palm 

 remains quite straight, undisturbed by tropical 

 storms, or is so flexible that trees standing in each 

 other's vicinity strike against each other, making an 

 extraordinay noise. In a very interesting article, on 

 the Coco de Mer, published February, 1865, in the 

 Technologist, by Mr. G. Clark, who seems to have 

 been on the spot, it is said " in strong breezes the 

 plant bend -considerably, while their elasticity causes 

 them to wave in the most graceful manner." Of the 

 root, the same writer says : — "The root is in some 

 cases bellshaped, and in other nearly hemispherical 

 and a vast number of rootlets radiate from it in all 

 directions except upwards; these extend to a great 

 distance around it, and form ad mil-able stays to resist 

 the strain which the play of so long a lever subjects 

 them ; and so well do they perform their office, that 

 I have never known an instance of a Coco de Mer 

 having been blown down." — Beniardin. 



Vegetable Origin of Coal.— Though exhibit- 

 ing little structure, there is no doubt of the vegetable 

 origin of all coal. In some cases, shells and remains 

 of insects, fishes, and even small reptiles, have been 

 found embedded with coal, but there are no appear- 

 ances of aqueous deposits of this kind in the sub- 

 stance of the mineral. Evidence of the mode of ac- 

 cumulation may no doubt be detected, not only in 

 the position of the innumerable leaves, twigs, and 

 stems of plants, in the neighbouring clays and sand- 

 stones, but in the substance of the coal itself. But 

 all kinds of coal have been so greatly altered in their 

 conversion, they have lost so much of various sub- 

 stances commonly present iu plants, in addition to 

 carbon; they have become so compacted and are 

 reduced so thoroughly to the condition of a simple 

 mineral, that the absence of vegetable structure 

 caunot be wondered at. It still remains a mystery 

 how coal was formed, or what combinations were 

 necessary to produce it. In most cases, especially 

 in thick beds, it represents a mass of vegetation that 

 must have taken many years, or a large area, to ac- 

 curemlate, but yet in some instances there is proof 

 that it must have been accumulated rapidly. That 

 it is generally associated with certain shales, with 

 ronstones, either in nodules or bands, and with 



sandstones more or less compact, and that in moss 

 cases, though not all, it seems to have been accu- 

 mulated near the mouths of large rivers or low 

 swampy flats, and in estuaries, are facts and infer- 

 ences that include the results of recent discoveries 

 and investigations in this matter. — Austed's Prac- 

 tical Geology. 



Botanical Congress. — An International Horti- 

 cultural Exhibition and Botanical Congress is an- 

 nounced to be held in London, in May, 1866. The 

 Congress will be restricted to two morning meet- 

 ings, when papers, previously printed and accom- 

 panied by translations, will be read and discussed. 

 The chair will be taken byM. Alphonse de Candolle, 

 who will deliver an opening address. Dr. Berthold 

 Seemaun is honorary secretary to the Congress, to 

 whom any communications should be addressed. 



MICROSCOPY. 



Reelection on the Retina. — During the sum- 

 mer, having the chrysalis of musquito under a low 

 power of the microscope, the part under immediate 

 observation being the eye, which in this state of the 

 creature's existence is simple, I was much pleased 

 and surprised to see the window-frame, and conse- 

 quently any object presented to the pupa's eye re- 

 flected on the retina. The hand with the fingers in 

 motion was beautifully defined. I employed day- 

 light and no condenser, the power not more than 

 eight diameters. I have never seen this mentioned 

 in any work on microscopy, aud hope some of your 

 readers may succeed in obtaining a sight of this in- 

 teresting object. — S., Oporto. 



Mounting Crystals. — I have been engaged 

 lately with crystalization in connection with the mi- 

 croscope and polarized light. I have only a few 

 hours occasionally to devote to the pursuit at night 

 after business, and I have no doubt a great many 

 other amateur microscopists are similarly situated. 

 It is therefore a great disappointment, night after 

 night, to lose beautiful slides through not knowing in 

 what medium to mount them. Eor instance, last night 

 I prepared two slides of pyrogallic acid and chronic 

 acid. If 1 tried to mount them "dry" they absorbed 

 moisture from the air and returned to a liquid state; 

 and in pure ," Canada balsam "or " glycerine " they 

 dissolved. Could not some one thoroughly experi- 

 enced and conversant in, and with the matter, pre- 

 pare a list of salts, and opposite each name put the 

 appropriate medium or mediums for that particular 

 salt ?— W. S. 



Aleyrodes. — This is a very pretty object pre- 

 pared for the microscope by mounting iu a dark 

 cell the perfect insect and its pupa case. The Aley- 

 rodes is a tiny white-winged creature, like a small 

 moth, about the size of a large pin's head, found in 



