102 Laical and Pupal Stafjea of Bibiu Johaiiniy L. 



are smaller than the others but more numerous. The protoplasm con- 

 tains many fine granules. 



The Colon, which follows the ileum, is of rather larger diameter, and 

 is less muscular than the ileum. It has a fine intima, outside which is a 

 layer of epithelium rather thinner than that of the ileum. The colon is 

 invested with circular muscle fibres similar to those of the ileum, but 

 they are neither so large nor so close together. Externally the colon is 

 covered with a delicate connective tissue membrane. 



The Rectum is of considerably smaller diameter than the colon. Its 

 epitheUum and intima are deeply folded, filling up much of the gut. The 

 muscular coat is well developed and composed of circular muscles, with 

 a connective tissue membrane outside them. 



The Nervous System. The nervous system of the Bihio Johannis 

 larva consists of a brain or supraoesophageal ganglion, a suboesophageal, 

 three thoracic and eight abdominal ganglia. The brain is two-lobed and 

 lies in the anterior part of the first segment of the body. The two lobes 

 are distinct but are closely connected. 



The suboesophageal ganglion lies directly below the brain, and is 

 connected with it by short but fairly fine oesophageal connectives, which 

 connect its anterior end with the anterior end of the lobes of the brain. 

 The head is almost entirely filled with the muscles of the mouthparts, 

 so that the brain is displaced into the first segment. In this latter 

 region, in larvae near pupation, the rudiments of the adult head may be 

 also found. 



The first thoracic ganglion lies just behind the suboesophageal, and 

 is nearly as large, the second is close behind it while the third is farther 

 back. The first ganglion is situated at the posterior end of the first 

 segment, the second lies in the front of the second segment and the 

 third in the front of the third segment. 



The abdominal ganglia are smaller, and are situated one in each 

 segment. The first seveii ganglia lie in the anterior region of their 

 respective segments. The last abdominal ganglion is considerably larger 

 than the others, and is situated toward the hinder region of the eleventh 

 segment. 



In the head is a small frontal ganglion which is connected with the 

 brain. 



The connectives between the ganglia are clearly double throughout. 



From the ganglia lateral nerves are given off, the distribution of 

 which was not studied. 



