Nov. 1, 1S66.] 



HARDWICKE'S SCIENCE-GOSSIP. 



249 



very plainly the gradations a hair goes through 

 (t to m). This latter had evidently been 

 broken ; but if one was to search attentively, a 

 perfect example of a hair with ten branches, regu- 

 larly disposed round the centre, could, no doubt, be 

 found. I have never seen one with more than this 

 number. 



Thus much for star-shaped hairs. At another 

 time I hope to give a description of some interesting 

 examples of simple and branched hairs. 



Arthur B. Cole. 



GASTRIC TEETH OF INSECTS. 



rpiIE first volume of Science Gossip contains 

 -*- most interesting papers under the title of 

 "What do crickets eat?" 



One of the impressions which these papers are 

 calculated to leave upon the mind of the reader is, 

 that crickets must possess wonderful digestive 

 powers to enable them to feel comfortable after a 

 meal of such material as leather, &c. They have, 

 indeed, good digestive powers, and they have an 

 efficient organization for the purpose. 



Besides the cutting instruments connected with 

 the head, crickets, and some beetles, have second 

 stomachs or gizzards. 



The gizzard is situated immediately below the 

 ordinary stomach, and in many cases it is furnished 

 with strong teeth, very curious in their structure, 

 and effective for the thorough grinding of food prior 

 to its passage into the digestive canal. 



The structure of the gastric teeth of the cricket is 

 well known to microscopists, few cabinets being 



books, for the sake of the general reader I give a 

 camera lucida sketch of two sets of teeth out of the 

 six rows of which the entire gizzard is composed 

 (fig- 236). 



Some beetles have gizzards, and these are worthy 

 of a careful examination, on account of the beauty 

 and variety in the arrangement and structure of 

 their gastric teeth. A few simple instances will 

 serve as illustrations. 



The gizzard of the common cockroach [Blutta 

 orieiitalis) contains five strong horny teeth : these 

 are not very remarkable for their beauty, but if the 

 gizzard be examined before it be slit down and 

 spread out, and while the teeth are in their natural 

 position, the walls will appear of a yellow colour 

 and the teeth of a rich brown, the whole not unlike 

 the appearance of a small artificial flower. 



There is a ground beetle, very common, about 

 half an inch in length, and of a shining black colour 

 {Pterostichvs niger). The gizzard of this beetle, 

 although interesting, does not contain teeth of any 

 appreciable size; and when it is considered that 

 some very small beetles have comparatively large 



SuTfU 



Fig. 236. Gastric Teeth of Cricket x 30. 



without the very attractive object which they afford. 

 As they have not been frequently figured in hand- 



Fig. 237. Gastric Teeth of Weevil x 30. 



gastric teeth, the suggestion strongly impresses 

 itself upon the mind, that with the study of the 

 structure of gastric teeth there should be associated 

 that of the formation of the mouth and the nature 

 of the food, as these three things evidently bear a 

 close relation to each other. 



A few years ago, the rose-trees of a large garden 

 in this neighbourhood were much injured by a brown 

 weevil of about a quarter of an inch in length, and 

 which I take to have been OtiorhjncJms picipes. 

 The gizzard of one of these (fig. 237) forms a beau- 

 tiful object. The teeth are in seven rows ; they are 

 of a deep red colour, and are composed of stiff hairs. 

 Each row is parted in the centre and laid down to 

 the right and left, and the teeth, if such they may 

 be called, are set in a striated membrane. 



