128 



Thus Captain Phillip was taking with him on his voyage to Australia a 

 plant of South American origin, that possessed thorns, and that supported a 

 growth of Wild Cochineal. That the latter was not the precious cochineal 

 insect may be inferred from Dr. De Simoen's testimony of the quality of Brazilian 

 cochineal quoted by Dr. Anderson in a previous letter also to Sir J. Banks 

 (Anderson, J., Letters, 1789, p. 12.) 



(3.) ANATOMICAL STRUCTURE OF PRICKLY-PEAR. 



As the destruction of prickly-pear by its utilisation may involve con- 

 siderations relating to its anatomical features, it may be pointed out these have 

 not been overlooked by botanical investigators. The best summary of their 

 work is perhaps that contained in Dr. Hans Solereder's comparatively recent 

 memoir On the Systematic Anatomy of the Dicotyledons. Of this, the English 

 translation, edited by Messrs. L. A. Boodle, F. E. Fritsch, and D. H. Scott, 

 and issued in 1908, devotes nearly ten pages (pp. 406-416) to the consideration 

 of the subject. Solereder summarises what has been recorded regarding the 

 stomata, cuticle, epidermis, hypodermis (coUenchyma), woody-tissue and its 

 components, thorns, excretory and secretory structures (mucilage cells and 

 canals, crystal cells (oxalate of lime), lactiferous vessels, idioblasts, &c., citing 

 many authorities often with regard to each. Several of these, together with the 

 particular feature in the plant's anatomy that has engaged attention, are more 

 fully mentioned in the references to Bibliography, with which this report con- 

 cludes. Of the principal writers thus referred to may be mentioned J. Schleiden 

 (1839), Gasparini (1842), Arloing (1877), De Bary (1877), Longo (1879) ; H. 

 Caspari (1883) ; Lauterbach (1889) ; and H. Vochting (1894). 



With regard to the oxalate of lime that is so conspicuous a feature in the 

 group plants under consideration, W. Pfeffer has stated in his " Physiologie" 

 that " in some Cactacese even 80 per cent, of the dry weight " consists of this 

 substance {vid. Edition Ewart, vol. I., p. 486, 1900) and Solereder also remarks 

 that oxalate of lime is sometimes excreted in enormous quantities in this order, 

 and quotes Schleiden to the effect that " as much as 85 per cent, of the weight 

 of the ash of the entire plant (in Cephalocereus senilis), is composed of it (Op. cit., 

 p. 413). In this connection, reference also may be made to Tryon (1911, p. 7) 

 and Shirley and Lambert (1914, p. 42). 



(4.) ADDITIONAL NOTES ON WILD COCHINEAL. 



A. Queensland Pest Pear and Wild Cochineal. 



Our inquiries have led us to conclude that, whereas the several kinds 

 of Wild Cochineal Insect {Grana sylvestre) attach themselves to different 

 kinds of prickly-pears, and sometimes with fatal results to their plant-hosts, 

 there is with regard to some a decided exclusiveness in their dietary. This 

 especially seems to obtain with Coccus indicus. Green, that is alike so injurious 

 in India, South Africa, and Queensland to Opuntia monacantha. Again, 

 there is the association of Nopalea cochinelifera, Linn., and Coccus confusus 

 newsteadi in the West Indies. 



With regard to our particular quest — the discovery of a Wild Cochineal 

 insect or insects inimical to the growth of, or even feeding upon, our commoner 

 Queensland pest pears, Opuntia inermis, DC, and the denizen of the Burnett 

 River Valley that Mr. J. H. Maiden has referred (we deem erroneously) to 0. 

 Dillenii, Haw., it may be added that we met with no satisfactory evidence 

 pointing to their existence. 



