THE LOCUST OR SHORT-HORXED GRASSHOPPER 361 



point to the seat of smell in these organs in the moths as in many 

 other insects. 



Like the majority of insects, the locust possesses a sense of 

 sight (cf. Fig. 183). It sees not only by means of the compound 

 eyes, which are homologous with the structures of this name in the 

 Crustacea, but also by means of another type of eye, the ocellus. 



Fig. 182. — .Sense-organs of insects. 



Left, longitudinal section of portion of caudal cercus of a cricket, Gryllus domeslicuf, 

 showing type of hair {sh) supposedly tactile in function, with its innervation, and another 

 type of hair that is bladder-like (6). Center, section through an organ of taste of an insect. 

 Right, olfactory sense-organ from antenna of the grasshopper, Coloptenus, with innervation. 



6, bladder-like sensory hair; c, cuticle or exoskeleton; h, hypodermis or epidermis; m, 

 membrane, or thin portion of cuticle; n (left), nerve; n (right), nucleus of sensory cell; 

 7(s, non-sensory setae; nr, nerve; p, olfactory pit with peg-like sensory process; pj;, pigment; 

 sc, sense cell; sh, tactile hair; ic, taste cup. (Left, after Vom Rath; center after Will, 

 right, after Hauser. From Folsom, "Entomology," copyright, 1906, by P. Blakiston's 

 Son and Co., reprinted by permission.) 



The ocelli are relatively simple in structure, consisting of a thick- 

 ened portion of the skeleton, which is transparent and functions as 

 a lens in condensing the light, and beneath this a modified portion 

 of the epidermis with which are connected the fibers of the ocellar 

 nerve. In some instances, however, their structure is more com- 

 phcated, as in the ocellus of a honey bee, shown in Fig. 183 C. In 

 this instance the pigmented epidermis not only forms a cup beneath 

 the lens, but is bent inward for a short distance, at the rim of the 

 cup, in the manner of an iris. The capacity of such an eye for 

 forming images must be limited, although it is constructed on a 



