Miscellaneous. 77 



slightly inclined in a spiral (as in the unicellular hairs of the corolla), as- 

 cending to the right, as viewed from the centre. The edge of the lower 

 portion of these hairs sometimes presents an almost even outline, but 

 frequently (and perhaps nearly always towards the extremity of the 

 hair) a slight irregular beading occurs, exactly as we might expect, 

 were the dots or markings occasioned by external matter ; but I am 

 not sure that this appearance is incompatible with the idea that they 

 may be openings or slits in a secondary deposit on the common wall 

 of the hair, wliich, from an examination, solely of the markings in 

 the central portions, we might conclude they were. I have not 

 detected in these hairs actual motion of the cell-sap, but mucilaginous 

 threads may be easily seen radiating irregularly from the nuclear 

 vesicle, indicating such a circulation. "With regard to the contents 

 of the nucleus I cannot certainly speak. Sulphuric acid diluted, 

 causes the primordial utricle to contract and lie in the interior as a 

 loose sac ; in some small cells the separation is not apparent after 

 twenty-four hours' action. 



A solution of chloride of calcium causes a partial dissolution of the 

 primordial utricle, certain bodies, perhaps including the true nucleus, 

 remaining visible. 



The epidermis of the iutervenal spaces of the under side of the 

 leaf consists of cells with a sinuous boundary, numerous stomata 

 formed by two crescentic cells applied by their extremities being 

 scattered about, 



Acicular raphides are of frequent occuri'ence ; they abound also 

 in the glandular stipules found between the petioles of the opposite 

 leaves. 



The application of pressure causes the escape of very numerous 

 raphides, together with a peculiar thick fluid. In some instances this 

 substance has a vermiform appearance when forced out of the en- 

 closing sac, o-\ving to its having been exuded, I suppose, through a 

 small orifice. 



MISCELLANEOUS. 



On the Coccidse of the Olive, Orange, Lemon, and Rose-bay, and on 

 the Maladies produced by them on those trees in the Province of 

 Nice and in the Department of the Var. By M. Robineau- 

 Desvoidy. 



The author proceeded to the South of France with the view of 

 ascertaining the cause of a malady which had long been prevalent on 

 the above trees in that part of the country, and which it was supposed 

 had made its appearance in the central and northern departments. 



This disease, called morfie by the Itahans, fumagine in the North 

 of France, consists in a thick, black crust which covers the trunks, 

 branches, &c. of trees, sometimes over a considerable extent of country. 

 The trees become arrested in their growth, languid and barren. 



According to historical accounts, this disease has not appeared 



