HARDWICKE'S SCIENCE-GOSSIP. 



147 



is the common resin sometimes called rosin, which is 

 applied to a variety of uses. There are several 

 kinds of turpentine, viz., Venice turpentine, procured 

 from the Abies larix ; Strasburg, from Abies pecti- 

 7iata ; Bordeaux turpentine, from the Pimis pinaster ; 

 and Chio turps, from the Pistacia terebinthis. 



Gum thus or frankincense, an odoriferous product 

 of the Boswellia scrrata. It is of slight use except 

 for its odour, which the Roman Catholics turn to 

 account in their churches. Employed also by the 

 ancient priests of Egypt, its odour destroying the 

 foul emanations from the sacrifices. It is imported 

 from India and sometimes the Levant. 



Asafcetida {Narthex asafcetida). This flows from 

 incisions made in the root of the tree. In colour it 

 is milky white, but after it has been dried it takes on 

 a pinkish tint and is curiously mottled. It has a 

 most unpleasant odour. Afghanistan and Persia is 

 the home of the tree. It is used medicinally as an 

 anti-spasmodic in cases of asthma. 



NOTE ON SIREX JUVENCUS. 



I SHOULD like to record the capture in Alton, 

 Hants, of two fine specimens of the saw fly, 

 (Sirex jiivencHs), male and female. The female was 

 taken September 18SS in Mr. Monk's chemist's shop, 

 and the male on the ground in the High Street last 

 summer. Both specimens were kindly given to me 

 by the captors, and were alive at the time. This 

 species of saw fly does not appear to be very abun- 

 dant, and certainly is not so numerous as Sirex 

 gigas. This is the first, and only two specimens of 

 S. juvencHS I have had the pleasure of seeing, 

 although I have been on the look-out for them some 

 time. 



At the same time, my opinion is that S. juveiiciis is 

 British, and probably in some localities is more 

 plentiful than in others. Sirex gigas, the largest of 

 these saw flies, is frequently taken in this neighbour- 

 hood, and many specimens (all females) I have had 

 brought and sent to me by friends, for the hornet. I 

 found one pinned on my front door ; and on another 

 occasion one was sent me securely fastened up with 

 string in a paper box labled " Mind the sting." 

 " Well," thought I, " what now ?— hornet ? " 



I carefully opened the box, peeped in, and — oh, 

 my ! — not a hornet, but a fine female .5". gigas, with her 

 long needle-like ovipositor, which had been taken for 

 the sting of a hornet. The male of this species I have 

 never seen alive. At the same time 6". juvencus was 

 taken in the chemist's shop, Rhyssa persuasoria, one 

 of the Ichneumonidae, was captured in the grocer's 

 shop of Mr. Butler, in this town ; and this came into 

 my possession. 



It is very fine specimen measuring from head to 

 extreme point of ovipositor 2| inches. The ovi- 

 positor alone is i| inches long, a fine instrument to 



probe timber for wood-boring larv:e, in which to lay 

 its eggs. Can any of our correspondents say to what 

 extent these saw flies are injurious to fir timber ? 

 Will they attack healthy standing trees, or only the 

 sickly ones, fallen timber, and fir-fencing ? Some 

 years ago I had an old fir post brought me com- 

 pletely honey-combed by larvce of S. gigas ; and 

 towards the outside of post were specimens of the 

 saw fly ready to emerge. To all appearance the saw 

 fly had laid its eggs in the post. I am quite aware 

 that it is the opinion of some, that the fly does not 

 attack the healthy trees, but only the dead ones. If 

 those of our correspondents who live close to fir 

 plantations would make a few observations, and 

 make them known through the medium of Science- 

 Gossip, we should get a good bit of valuable 

 information. 



J. BOGGUST. 



LEFT BEHIND. 



By the Rev. Hilderic Friend, F.L.S., Author of 

 " Flowers and Flower Lore." 



THE joints and sweets had been removed, and a 

 fine piece of cheese— whether Gruyere, Gon- 

 gales, or other, I am not connoisseur enough ito 

 determine — but at any rate, a handsome, speckled 

 green and white piece of cheese was brought on, 

 whereupon our garrulous friend at the head of the 

 table broke forth. " I saw such a thing the other 

 day as I never saw before in my life. What funny 

 stuff cheese is under the microscope ! " 



Now I pride myself upon being rather clever at the 



Fig. 108. — Willow-mite 

 {Tetranychus salicis). The 

 dot within the ring represents^Fig. 109.— Elm-mite [TctranycJius 

 the natural size. ulmi), 



microscope, and I felt convinced that my friend the 

 cheese-parer had not been looking at cheese under 

 the microscope. Its pasty form presents no attrac- 

 tions like those of the bonnie wee mites which the 

 cheese-fancier likes to hear crack, crack between his 

 teeth, as he takes a morsel of the most hvely portion 

 and devours it after dinner as an antidote to indiges- 

 tion. I therefore ventured to suggest to my friend 

 that perhaps he had been inspecting- som.e cheese- 

 mites. Exactly so ! 



H 2 



