iSTATU RAL HISTORY. 



837 



of the testicle, in cases of Taricose 

 veins of the spermatic ciiord, wiiich 

 not only produce very violent local 

 inflammation, but also a considerable 

 degree of symptomatic fever, it is 

 impossible not to be surprised, that 

 the results should be so very diOcr- 

 ent, since we are led to believe, 

 upon a general principle, that parts 

 are sensible in proportion to their 

 vascularity, and that all the organs 

 of sense, when infiamcd, are more 

 exquisitely so than any other parts 

 of the body. 



The tongue appears to have a 

 power of throwing oft' its sloughs 

 in a shorter time than any other 

 part. Eight or nine days is the or- 

 dinary time of a slough separating 

 from the common parts ; in the 

 boy's tongue it was only five. 



llaving stated the information we 

 derive from these cases, respecting 

 the structure, sensibility and irrita- 

 bility, of the tongue; it now re- 

 mains to mention the advantage to 

 be derived from them in a profes- 

 sional view ; and although this is 

 not directly in the line of the pur- 

 suits of this learned society, yet, so 

 strongly is it connected with huma- 

 nity, that it cannot be said to be fo- 

 reign to them, or undeserving their 

 attention. 



The information derived from 

 these cases, enables us to attempt, 

 with safety, the removal of any part 

 of the tongue which may have taken 

 on a disposition to become cancer 

 ous. As this disease in the tongue 

 always begins in a very small por- 

 tion of that organ, it is in the early 

 stage, more within the reach of re- 

 movai, fhnti in any other part of the 

 body ; and, as the glands of the 

 tongue are independent of each 

 other, the canci-rous disposition by 

 which one of them it> attacked, docs 



not so readily communicate itself 

 to the others; and the part may be 

 removed with a greater degree of 

 security, against a future recurrence 

 of the disease, than in other cases 

 where this malady attacks a portion 

 of a large gland, the whole of which 

 may be under the influence of the 

 poisou, long before there is any ap" 

 pearance of its being diseased. 



ylccount of the Genus Aphis, or 

 Plmit-Louse. 



From a great degree of general 

 similarity in the insects of this genus, 

 their true specific characters are 

 often very difficultly determinable. 

 They frequent the leaves, stems, 

 and tender shoots of plants and 

 trees, and are popularly known by 

 the name of plant-lice. They are 

 observed to be viviparous in summer,^ 

 and oviparious in autumn ; but the 

 most wonderful part of their his- 

 tory is the povver of continued im- 

 pregnation, through a great many- 

 descents, as far as the fifth, eighth, 

 twelfth, and even, according to 

 some observations, the twenty- 

 seventh generation. A pregnant 

 female aphis, kept by itself, pro- 

 duces perfectly formed young ones, 

 which, though kept separate, will, 

 after a certain period, produce 

 others, which arc also themselves 

 impregnated, and thus the breed 

 may be continued as before niea- 

 fioned. 



This wonderful faculty in the 

 insects of the present genus appear- 

 ed, at its first publication, so extra- 

 ordinary as to excite no small de- 

 gree of scepticism in the philosophi- 

 cal word. The observations how- 

 ever of Bonnet, Reaumur, Lyonett, 

 and o'lers, havcamply confirmed its 

 3 H 3 > trutb. 



