ACARID^. , 665 



genus Cheyletus is remarkable for having the maxillae very large, 

 and like a pair of legs, with the ends tripartite, the outer 

 division being curved and clawlike, while the two innermost 

 are slender lobes pectinated on the inner side ; the mandibles 

 are style-like. A European species (Fig. G40) feeds on Cheese- 

 mites. It is thought by Mr. R. Beck that another species of 

 Cheyletus is parthenogenous, as "he obtained several genera- 

 tions from the first individual, without the intervention of a 

 male." (Science-Gossip, 1869, p. 7.) Mr. J. II. Gregor}', of 

 Marblehead, Mass., has found a species of this geinis, which we 

 may call Cheyletus semmivorus (Plate 13, fig. 6). It injured the 

 seeds of the cabbage stored up during the winter by sucking 

 them dry. Tlie genus Tiiroghjphus is known by the body being 

 elongated oval, with scissor-like mandibles, and outstretched 

 four-jointed feet, with a long stalked sucking disc at the end. 

 T. doviesticus DeGeer is in Europe common in houses, 



Mau}^ people have been startled by statements in newspapers 

 and more authoritative sources, as to the immense numbers of 

 sugar mites, T. sacchari (Fig. 641), found 

 in unrefined or raw sugar. According to 

 Pi'ofessor Cameron, of Dublin, as quoted 

 in the "Journal of the Franklin Insti- 

 tute," for November, 1868, "Dr. Hassel 

 (who was the first to notice their general 

 occurrence in tlie raw sugar sold in Lon- 

 don) found them in a living state in no 

 fewer than sixt3'-nine out of sevent3'-two 

 samples. He did not detect them in a 

 single specimen of refined sugar. In an '^' 



inferior sample of raw sugar, examined in Dublin by Mr. 

 Cameron, he reports finding five hundred mites in ten grains 

 of sugar, so that in a pound's weight occurred one hundred 

 thousaud. Thc}^ appear as white specks in the sugar. The 

 disease known as grocer's itch is, undoubtedl}-, due to the 

 presence of this mite, which, like its ally the Sarcoptes, works 

 its way under the skin of the hand, in this case, however, of 

 cleanly persons. 



Closely allied to the preceding is the Cheese-mite, T. siro 

 Linn., which often abounds in newly made cheese. Lyonnet 



