402 

 GENERAL NOTES. 



ADDITIONAL NOTE ON THE SUGAR-CANE PIN-BORER. 



We have considerable additional correspondence relative to the dam- 

 age now being done by Xylehorus pubescens to the sugar-cane crop in 

 Barbados, Trinidad, and St. Vincent, as mentioned in our last num- 

 ber. It seems that the insect was investigated to a certain extent by 

 Mr. Herbert H. Smith in the Island of St. Vincent, and that Mr. T. D. 

 A. Cockerell, of Jamaica, has also given some attention to the matter. 

 Both of these gentlemen agree with us that the Xyleborus can not be 

 the prime author of the damage to cane, the former considering that 

 it only follows the attacks of the Larger Sugar-cane Borer {THatrwa 

 saccharalifi), while the latter thinks that it usually follows the work 

 of a weevil {Sphenophorus sp.). This further correspondence has 

 developed the interesting fact that the insect is by no means confined 

 to the sugar cane, Mr. F. Carmody, the Government chemist at Port 

 au Spain, writing us that it breeds in Mahogany, while Mr. H. Carac- 

 ciolo, also of Port au Spain, has ascertained that the alarming increase 

 of the insect is coincident with the recent and general change in the 

 method of disposing of the crushed cane — magass or bagasse. For- 

 merly, he writes us, it was the custom of planters owning sugar mills to 

 burn this refuse, whereas recently they h;ive begun to use it as manure. 

 The scattering of quantities of this dead vegetable matter through the 

 fields must afford a most appropriate nidus for the beetles, which doubt- 

 less oviposit upon it very extensively. Their very numerous offspring, 

 developing at the time when the bagasse has become too decomposed 

 for further oviposition, will naturally take to such canes as are weak- 

 ened by the attacks of the other insects mentioned, or even to healthy 

 canes. The resumption of the old practice of burning this refuse will 

 undoubtedly cause a decrease in the number of the insects. 



THE BLOOD TISSUE OF INSECTS. 



Dr. William Morton Wheeler, of Clark University, Worcester, Mass., 

 has just completed a series of three articles entitled "Concerning the 

 ' Blood tissue ' of the Insecta," in Psyc/t<'. The first article appeared 

 in February, 1892, the second in March, and the third in April. The 

 subject is one which has been comparatively little studied, and Dr. 

 Wheeler has had a practically new field. Under the head of blood 

 tissue he includes the following structures: (1) the blood corpuscles; (2) 

 the fatty body proper; (3) the pericardial fatty body ; (4) the cenocytes; 

 (these four structures have already been classified as blood tissues by 

 Wielowiejski, and to them Dr. Wheeler adds the following:) (5) the 

 garland-shaped cord of Muscid hirviB, and (6) a peculiar organ found 

 in the embryos and young larAii? of Blatta and Xiphidium, called by 

 Dr. Wheeler the suboesojjhageal body. The conclusions which he 



