Notes, iv. 6 — 8. 231 



sanitary, educational, and other functions. A. has another term of comparison for such 

 a body, viz. "the Delphian knife" {Polit. i. 2, 3), an implement apparently used for 

 many distinct purposes in the sacrificial rite. 



16. The anterior pair of legs are remarkably long in some insects (ICirby, Bridg, Tr. 

 ii. 180) ; with what use it is difficult to say. Sometimes at any rate it seems to be 

 a provision to enable the male to secure the female, the peculiarity being confined to, 

 or most marked in, the former sex. The explanation given by A. can hardly be the 

 correct one; for the anterior pair are not specially elongated in ants or bees, though 

 these are insects that use their legs to dress themselves. 



17. In such insects as are slow walkers all the legs are, as a rule, of much the same 

 length ; in those that run quickly all the legs are elongated, the hinder pair being the 

 largest ; in swimming insects, and still more in leapers, the hind legs are much longer 

 than the rest. In fleas the difference is not so marked as in grasshoppers ; nor do fleas 

 jump, like the latter, exclusively from the hind legs, for, having placed one in a glass 

 tube under a microscope, I have seen it hop with the anterior legs. 



18. Literally " resemble a rudder," but I have slightly paraphrased the expression to 

 render it intelligible to those who may not know how a Greek ship was steered. In place 

 of a single rudder, as in a modern ship, there were usually two, one on either side of 

 the stern, resembling large oars, and moved in the same way as the other oars. The 

 size and position of these rudder-oars render, therefore, the comparison to the posterior 

 legs of the locust or grasshopper a very apt one. The resemblance, moreover, extends 

 to the functions. "Whoever," says Kirby, "has seen any grasshopper take flight or 

 leap from the ground will find that they stretch out their legs, and like certain birds use 

 them as a rudder " {Bridg. Treat. iL 162). 



19. Cf. iv. 12, Note 10. A.'s meaning is expressed more intelligibly elsewhere {H. A. 

 iv. 7> 9)> "In some jumping insects the hind legs are simply larger than the rest, while 

 in others they resemble rudder-oars, being bent backwards like the [hind] legs of 

 quadrupeds." 



(Ch. 7.) 1. Cf. iv. 5, Note 25. 



2. Cf. ii. 10, Note 5. 



3. Cf. iv. 5, 22-41. 



4. "Aristotle in his Hist, of Animals mentions more than once a shell-fish under the 

 name of Solen in such expressive terms that we can scarcely doubt its identity with the 

 razor-fish, in all probability the Solen marginatus. He states that it buries itself in the 

 sand, perpendicularly, even to the depth of two feet, and can rise and sink in it, but does not 

 leave its hole ; that it does not spin a byssus like other Testacea ; that it is alarmed by 

 noise, and buries itself rapidly when frightened ; that the valves of the shell are connected 

 together at both sides, and that their surface is smooth. Such an enumeration of 

 characters indicates how carefully the great philosopher studied razor-fishes, and with 

 what interest he watched their doings and chronicled their fears " {Forbes and Haiiley, 

 Brit. Mollusca, i. 240). 



5. The ordinary position of most living bivalves is not on their side but vertical, with 

 the opening between the valves downwards. This probably led A. to the conclusion 

 that the head, or what answered to it, was downwards, so as to take in food from below. 

 As to roots of plants, cf. ii. 3, Note 10. 



6. Cf. iv. 5, Note 48. 



(Ch. 8.) 1. The Crustacea are called by A. Malacostraca, ue. soft-shelled, or 

 sometimes Scleroderma, i.e. hard-skinned, and are defined by him as bloodless animals 

 that have their hard matter on the outside and their soft parts within ; the hard part, 



