June, igoi] 



PSYCHE. 



209 



groups of setai\ of which five pairs may 

 lie noted, represents a segment. The ab- 

 sence of all paired appendages back of 

 the head is to be noted. [Make a draw- 

 ing of the whole body of the 

 larva from a lateral aspect.] 



Internal Anatomy. (Fig. B. ) 



[Technical note. With fine scis- 

 sors cut open the body along the 

 median line of the dorsum, cut- 

 ting through only the body wall. 

 Put the specimen in a* dissect- 

 ing dish, pin out the cut edges 

 with ribbon pins, and cover 

 with water.] 



Alimentary canal and accessory 

 parts. The alimentary canal ex- 

 tends through the middle of the 

 body cavity, nearly wholly en- 

 closed, in a thin perforated sheet 

 of fat, adipose tissue. The canal 

 consists, first of a slender tube, 

 the oesophagus, embraced by the 

 circufnoesophageal ni'iTe commis- 

 sures and the brain lobes; second, 

 of an abruptly dilated conical 

 portion, the proventriiulus ; 

 third, of a portion immediately 

 behind this and not sharply 

 marked off from it, the elongated 

 ventriculus, bearing at its ante- 



rior end four elongated pouches, the 

 gastric caeca. In the sheet of adipose 

 tissue surrounding the ventriculus sev- 

 eral slender convoluted tubules may 



* For a dissecting dish use a shallow tin 

 dish, about 5 inches long. 3 inches wide and 

 I inch deep, into which melted paraffine has 

 been poured to a deptli of 5 inch and allowed 

 to cool. On the smooth surface of the paraffine 

 specimens may be pinned out with short pins 

 and covered with water. Always dissect under 

 water, as the water holds up the loosened parts. 



HOLORUSIA RU8tGI>tOSA. 



A, larva. B, dissection of larva, showing all organs except the 

 muscles and ventral nerve chain, k, head; ant., antenna; i. b. res.. 

 imaginal bud of pupal respiratory tube ; /. h. wg.. imaginal bud of wing ; 

 i.b. ins. I., imaginal bud of mesnthoracic leg; /. b. h , imaginal bud 

 of balancer ; i. b. tnt. I., imaginal bud of metathoracic leg (the imaginal 

 buds of fore legs are concealed by head capsule); sal. gl., salivary 

 gland (the other salivary gland is removed); br., brain; (T«. , oesopha 

 gus; firm'., proventriculus; susfi.. suspensorium ;,^. c, gastric coecum ; 

 vent, ventriculus: ^r., trachea; <7^, /«,, adipose tissue ; mat. tub., Malpi- 

 ghian tubule; d. z>., dorsal vessel; iv. m., wing muscles of pericardium ; 

 snt. int., small intestine ; tes , testis ; /«/. c., intestinal caecum ; v.d., vas 

 deferens; /. int., large intestine; sp., spiracle; term, pr., terminal 

 processes. 



