VARIOUS 1 153 



2) A grey 'male obtained by crossing a wild male with a French sil- 

 v^ered female was crossed with the German female " Edelweiss " ; the pro- 

 geny numbered 4 : 2 black and 2 grey. Of these latter there are still i 

 black and i grey individual, both having reached half the normal growth. 

 The black rabbit already shows white hairs in the black coat, thus recaUing 

 the silvered granddam. These 2 subjects have supple fur, but they still 

 possess the timid character of the wild rabbit. 



3) The second litter from the above cross consists of 4 animals now- 

 aged 5 weeks, 3 of them being black and i gre}'. 



4) On crossing a male rabbit with a female of the same litter originat- 

 ing from the cross wild male x French silvered female, a litter was recently 

 obtained which has not yet been studied, but which meanwhile already dis- 

 closes the interesting fact that the mating of the parents of this litter, who 

 are brother and sister, is fertile. 



895 - Gum Lac and the Breeding of Tachardia. — i. duporti^. i^'insectea stick-iac 



II. H.\UTEFEtnLLE 1,. I,a gomme laque et son traitement industriel, in Bulletin econo- 

 mique de VIndochine, Nos. 112 and 116, pp. 182-189 and 872-994. Hanoi-Haiphong, March- 

 April and November- December 191 5. 



This study contains a summary of ten years of research and observa- 

 tions carried out by M. Hautefeuille. The stick-lac insect, Tachardia 

 lacca R. Bid., known also under the names of Carteria lacca Sig. and Coccws 

 lacca Kerr, is one of the rare useful cochineal insects ; it produces gum lac 

 and also a red colouring substance termed lac dye by the English. 



In India, where this product is ver\- important, several species of Tachar- 

 dia are probably known, or at any rate several varieties of Tachardia lacca, 

 which explains the contradictions in the information supplied bj' different 

 authors. Duport describes the insect, giving general information as to 

 its life history, with a separate description of the female, the male, and the 

 method of reproduction. He also enumerates the enemies of Tachardia 

 and among others: ants, the larval forms of Noctuidae and Tineidae, and 

 some Hymenoptera belonging to the family of Braconidae and Chalcididae. 

 Hautefeuille next studied gum lac and its industrial preparation. 

 Gum lac should not be confused with lac of vegetable origin derived from 

 Rhus vernicifera in Tonkin. Gum lac is a half -waxy, half-gummy secretion 

 of an insect living in innumerable colonies on some plants in India. It has 

 many important industrial uses, and the trade, as shown by the tables ap- 

 pended to the paper, attains considerable proportions. India exported 

 on the average, during the 11 years 1903 to 1914, 17 736 tons per year of an 

 approximate value of about £ 356 641 at a unit price of 11.68 d. per pound. 

 Indo-China during the period 1906-1914, exported on the average i 092 249 

 lbs. per year, for £ 24 190, at the average unit price of 5.67^. The range 

 of the lac insect lies within a vast rectangle enclosing Tonkin and the 

 northern tracts of British India. The Dictionary of Economic Products of 

 India by G. Watt gives the list of the plant species on which the lac insect 

 is able to live ; this list is reproduced by the writer with the addition of 

 some further species reported by the Forestry Department of Assam. This 



