Nov, 



!■] 



SCIENTIFIC NEWS. 



461 



From a congener of the cochineal insect is obtained 

 lac, which is so largely employed in the manufacture of 

 sealing-wax and of various varnishes ; and from it is 

 also procured a crimson dye which possesses some little 

 commercial value. In the years 1 807-1 809, indeed, the 

 sale of this dye at the India House, in point of actual 

 colouring matter, was estimated as equivalent to half a 

 million pounds of cochineal. The dye, as in the true 

 cochineal, appears to afford nourishment to the young 

 grubs until they leave the protecting shell into which the 

 dead body ot their mother collapses. 



The economic entomologist can scarcely fail to be 

 struck with the fact that these valuable insects are closely 

 related to some of the most mischievous. Thus, on one 

 side of their family, as it were, they are connected with 

 the scale insects, or mealy bugs, which are so destruc- 

 tive to many of our fruit-trees and cultivated plants, while 

 on the other they are allied to the aphis, that greatest of 

 all the insect pests which vex the farmer's heart. Even 

 if it be true that a man may be known by his friends, 

 certainly an insect is not to be known by its relations. 

 And it is quite possible that we may ultimately find of 

 value many insects which are either noxious themselves, 

 or which are at least closely related to others of the most 

 highly mischievous character. A green dye, for instance, 

 has been extracted from the caterpillars of the cabbage 

 butterfly. And as our knowledge of natural history in- 

 creases we shall doubtless be obliged to alter our present 

 views with regard to many insects, and to detect in the 

 future a friend where now we see but a foe. 



A Hybernating Dragon-fly. — It may interest ento- 

 mological readers to know that a certain European species 

 of dragon-fly is in the habit of hybernating in the imago 

 s'.ate, which singular discovery has only very recently 

 been made by a well-known German specialist. It is 

 not at all unimprobable that other species may be dis- 

 covered to hybernate also, since so very little has hitherto 

 been done towards the elucidation of their economy. 

 Most dragon-flies pass the winter in the larva state, 

 and seldom allow themselves to become torpid, even in 

 the most severe weather. 



The Batrachia of Southern India. — In a work 

 recently published by Mr. Edgar Thurston, of the 

 Government Museum at Madras, fifty-five species of frogs, 

 toads, and ccecilians are enumerated. The newts, or tailed 

 batrachians, are not represented in Southern India. In 

 Ceylon only thirty-three species of batrachians occur, 



I eighteen of which are found also on the mainland. The 

 Madras Weekly Mail, noticing the above work, adverts to 

 the gymnastic feats of the " chunam frog," A genial 

 writer, seated one evening in his garden, was finishing 

 an interesting chapter, when an adventurous " chunam 

 frog " lighted like a dab of mud behind his right ear, 



v and there stuck ! The batrachians of Southern India, 

 however, are as yet very imperfectly known. 



The Size of the Cobra.- -In the Madras Weekly 



Mail we find a controversy raging as to whether a 



serpent shot by a certain " Jungle- wallah" was a cobra 



\Naja tripudians) or a hamadryad (Ophiophagus elaps). 



3ne writer offers a reward of 25 rupees to any one who 



an produce a cobra over seven feet in length, whilst the 



lamadryad reaches double that length. The latter 



nake, further, inhabits wild forests only, whilst the 



obra is equally at home in the city or in the wilderness 



The hood of the cobra, with the well-known spectacle 

 markings, is represented in the Ophiophagus only by a 

 small dilation of the skin lower down the back, without 

 spectacles. The Ophiophagus has, moreover, indistinct 

 yellowish bands across the body. It is clearly estab- 

 lished that this snake attacks passers-by without any 

 provocation. 



Causes of Variation in Organic Forms. — Professor 

 C. V. Riley (American Association, reported in Science) 

 concludes a memoir on this subject by saying, " All 

 that evolution recognises is the transmutability — the 

 generic identity— of the forces of nature, which in their 

 aggregate action may properly be defined as omnipresent 

 energy. We know, as a matter of the simplest observa- 

 tion, that this combined force or energy is essential to 

 the continuance of life, not only upon our planet, but 

 deductively in the universe. We are justified in infer- 

 ring that it is capable, under fit conditions, of originating 

 life from what we know as non-living matter. Evolu- 

 tion, in fact, inevitably leads to the inference that vital 

 force is transmutable into and derivable from physical 

 and chemical force." 



Species of Termites. — Of these insects, twenty-four 

 distinct species are now recognised, nine of which are 

 African, nine American, two Asiatic, and two European. 



New Evidence against the Squirrel. — A corre- 

 spondent of the Field records the fact of a squirrel 

 attacking a green woodpecker and disabling it, so that 

 its rescuer had to put the poor bird out of pain. We 

 think that all lovers of birds ought to declare war 

 against this felonious rodent. 



Co-operation of Frost and Destructive Insects. — 

 Professor von Ettingshausen observes that trees which 

 have suffered from frost are especially liable to be 

 attacked by the cockchafer (Meloloutha maialis). In- 

 versely, trees which have been damaged by destructive 

 insects are unusually sensitive to frost. 



Report of the Commissioner of Agriculture, 1887. Wash- 

 ington : Government Printing Office. 

 This report contains a large amount of valuable infor- 

 mation on the injuries occasioned by insects, birds, para- 

 sitic fungi, etc., and on the means for their repression. 

 Especial attention is due to the experiments on the food 

 of hawks and owls, birds much more useful than is gene- 

 rally supposed. If we leave out of consideration the 

 great horned owl, a bird which no longer occurs in 

 Britain, it will be seen that the food of the remainder 

 consists essentially of mice. For the ffbrned owl little 

 can be said, as his food is almost entirely composed of 

 game and poultry. Even the smaller hawks seem to do 

 more good than harm, since their stomachs were found 

 to contain mice and grasshoppers in profusion. 



On the sparrow question we find no new facts, the 

 evidence against this " winged rat " being found so con- 

 clusive that no further inquiry is needed. The opinion 

 arrived at is expressed in such phrases as " The best 

 methods of abating the sparrow scourge." The agent 

 recommended is grain or maize meal, fifteen parts of 



