58 



HARDWICKE'S SCIENCE-GOSSIP. 



BOTANY. 



Rare Plants. — I wish to record the re-discovery 

 oi Saxifraga hirculus on July 31, growing in marshy 

 ground near Loughnaroon, townland of Glenbuck, 

 parish of Rasharkin, co. Antrim. It was found in 

 1837 by the late Mr. David Moore, curator of Glas- 

 nevin. When on the Ordnance Survey, I found it 

 growing sparingly. I found the parsley-fern and 

 beech on Slievananee, co. Antrim, and both the filmy 

 ferns in Glendun, in the same county. — S. A. Brenan. 



Mimicry of Mint by Dog's Mercury. — In 

 answer to your correspondent P. S. Taylor, respecting 

 "mimicry of mint by dog's mercury," I think he 

 has jumped at conclusions too quickly. The same 

 occurrence of Mercurialis perenuis took place in my 

 own mint bed, but it also occurred all over the garden 

 where the ground was bare and the sown crops had 

 not come up. This was also the case with the mint 

 bed which had been newly planted and failed, and 

 hence the so-called mimicry. In former years when 

 the mint has done well, although dog's mercury has 

 occurred in other parts of the garden, where no mimicry 

 could be supposed, the mint has been singularly free. — 

 CoUis IV. 



Sagittaria sagittifolia. — In answer to your 

 correspondent B. B., respecting Sagittaria sagitti- 

 folia, there is nothing at all unusual in the appearance 

 of the two small hard tubers about the size of 

 snowdrop bulbs, although I do not think the fact is 

 generally known ; but anyone in taking up one of 

 these plants with care, even in early summer, and 

 when in full foliage, will be sure to find these bulbs 

 on stalks varying in length according to the nature 

 of the soil through which they have to pass ; these 

 stalks being very brittle, will break, and the bulb be 

 lost, unless great care is taken, and this may account 

 for them not being noticed. It appears that the plant 

 reproduces itself by these as offsets as well as by 

 flower and seed. Early this summer, accompanied 

 by an eminent botanist, I removed some of these 

 plants from the river Roden, Essex, with these stalks 

 and tubers intact, and he then mentioned that the 

 fact was new to him, although I, a perfect novice, had 

 often noticed them. — C. IVUlinott. 



To Skeletonise Leaves. — The leaves should be 

 perfect. Place them in a vessel containing water and 

 allow them to remain for three weeks, or longer, accord- 

 ing to size ; then examine, and if the colouring matter 

 appears soft, place the leaf on a china plate, and with 

 a camel-hair brush dipped in water carefully remove 

 the thin part of the leaf from between the veins. 

 Should it not be possible to do this at one operation 

 without injury to the veins, <.S;c., allow the leaf to 

 remain in water a short time longer, then repeat the 

 operation until a perfect skeleton is obtained. 

 Richard A. CromblcJioliiu. 



The late George Bentham, F.R.S. — Every 

 English botanist will hear with profound regret of the 

 death of this veteran botanist at the ripe age of 83 

 years. His name is associated with the development 

 of the natural system almost more than any other 

 man's, and his intellectual vigour and elasticity was 

 shown by his quick percejition of the value of the 

 evolution theory to j^ractical botany. He continued a 

 vigorous worker almost up to the last. 



The Chemistry of Plants. — Messrs. Berthdot 

 and Andre, two French scientists, have given an 

 account of their recent researches in organic botany. 

 They have attempted a complete analysis of a vege- 

 table organism, with a view to determining the 

 chemical equation during its development from the 

 fertilised germ to its fructification and reproduction. 



GEOLOGY, &C. 



Geology at the British Association. — 

 Geology this year was extremely local, though the 

 locality was a great continent. The address 

 of the president, Dr. Blanford, has an important 

 general bearing on the characteristics of the locale of 

 this year's meeting. He attacked a fallacy which has 

 exercised a pernicious influence in geology, and which 

 it will take some time to thoroughly eradicate. It 

 has been very rashly assumed by some geologists that 

 because we find the remains of similar animals in 

 certain strata in regions far distant from each other, 

 as Europe and America, Africa and Australia, there- 

 fore these strata must necessarily be of the same 

 geological age. Dr. Blanford entered with great 

 minuteness into the question, showing, by the 

 production of numerous actual examples, how absurd 

 the hypothesis often is. The subject is one having 

 important bearings on the question of the develop-- 

 ment of life in various parts of the globe. It was 

 specially appropriate in the president to take it as the 

 topic of his address at the first meeting on the 

 American continent ; for naturally American and 

 indeed English geologists attempt to co-ordinate 

 American with European formations and fossils. 

 Indeed, one of the most prolonged discussions turned 

 to a large extent on the relations of the one to the 

 other. Professor Bonney introduced it in his paper 

 on the Archaean Rocks of Great Britain, which was 

 supplemented to a large extent by papers by Professor 

 Sterry Hunt, the Rev. J. F. Blake, and others. This 

 was the introduction to American soil of a controversy 

 that has been waging among English geologists for 

 some years. Canada is the home oiEozoon Catiadcnsc, 

 to which there was allusion in one or two of the 

 papers ; but its true nature, whether organic or 

 inorganic, was not seriously discussed. Section C 

 abounded with papers of interest, and not the least 

 interesting were those by the Rev. E. Hill and others 



