222 AEISTOTLE S ANAIMA, 



considerable difficulty, but it may be said that, in some essen 

 tial respects, they were inferior to that indicated by Aristotle. 



About sixty Entoma, are described or mentioned by 

 Aristotle, but only a comparatively small number of these 

 can be satisfactorily identified. Some of these will next be 

 considered. 



He compares the hind legs of the Akris or locust to the 

 two rudders used in some Greek ships, one on each side 

 towards the stern,* and says that it produces a sound by 

 rubbing itself with its pedalia, rudders or hind legs.t 



He was aware that it deposits its eggs a short distance 

 below the surface of the ground, and that its young emerge 

 in a form very much like that of the parent, there being no 

 distinct metamorphosis.! It is probable that the locust to 

 which he refers is the migratory locust (Pacliytylus migra- 

 torius) of south-eastern Europe. 



The cicada is clearly referred to by Aristotle in many 

 passages, although some of these passages do not correctly 

 describe the characteristics of this insect. The cicada has a 

 piercing and suctorial beak, by which it sucks the juices of 

 plants. Aristotle says that the Tettix (Cicada) has a tongue- 

 like process, by which it feeds on dew only. The idea that 

 the cicada feeds on dew only is commonly found among the 

 ancient writers. 



The singing of the cicada is produced by membranes in 

 chambers covered by scaly plates on the under side of the 

 abdomen and just behind the thorax ; the membranes are 

 vibrated by the action of certain muscles. Aristotle says 

 that the Tettix sings in consequence of the friction of the 

 air on the membranes beneath the liypozoma or part close 

 to the division between the thorax and abdomen. || 



The male cicadas sing, the females being silent; this was 

 exceedingly well known to the Ancients, and is referred 

 to by Aristotle. U He also refers to large cicadas, called 

 Achetai, which sing, and small ones, called Tettigonia, 

 which do not sing, or sing but little.** This passage, 

 especially the last part of it, is difficult to understand, but 

 it is probable, from the context in H. A. v. c. 24, that 

 Aristotle intends to refer to large and small cicadas differing 

 in species. 



* P. A. iv. c. 6, 683a. f H. A. iv. c. 9, s. 2. 



I Ibid. v. c. 17, s. 2, v. c. 23, ss. 1 and 2. 



Ibid. iv. c. 7, s. 7 ; P. A. iv. c. 5, 682a. 



|| H. A. iv. c. 9, s. 2. IT Ibid. v. c. 24, s. 4. ** Ibid. v. c. 24, s. 1. 



