riDlv'OUS TISSUE rRODUCED AS A liEACTlON TO INJURY. 599 



tive tissue, bnfc diffcriiio' in struct lire. Tlie larger, seini-trans- 

 parent and wliitisli, consists of striated fibres. The fibi-es of 

 the smaller, whicili is opaque and dead white, and lies against 

 the posterior sni'f;ice of the larger mass, ;ire non-striated. It 

 was into the larger mass that all material in our experiments 

 was introduced. 



There is a lai-ge blood supply to the muscle from the 

 adductor nrtery (Dakin, 2), and it contains numerous lacunar 

 spaces. Scattered through it iire numerous strands of con- 

 nective tissue. These contain fibroblasts with deep staining 

 nuclei and long fibrillar processes. 



The digestive gland has a tubular structure and com- 

 pletely surrounds the stomach, into which its ducts open. 

 The ducts break up into numerous alveoli, which ramify and 

 ultimately form creca. 'J^he ducts are lined with ciliated 

 epithelium, and the alveoli with secreting cells. These secre- 

 ting cells are said to degenerate and become filled with a 

 granular pigment, and are ultimately shed into the lumen of 

 the ducts (Dakin, 2). Thus in their younger stages they 

 appear to have a secretory, and in their later stages an excre- 

 tory function. In addition to these glandular cells, fibrous 

 connective tissue and unstriated muscle-fibre are present. 

 The ducts contain particles of food material, algae, diatoms, 

 and bacteria,, and consequently as a rule septic conditions 

 prevail in the experiments. 



The blood of Pec ton maximus is a slightly cloudy, 

 colourless fluid. It does not coa"ulate. but when shaken a 

 number of small, white, floccular masses appear, which soon 

 fall to the bottom of the tube, leaving the supernatant (iuid 

 clear and transparent. These masses consist of blood-cor- 

 puscles agglutinated to form plasmodia. 



The corpuscles, although varying in size, appear to be only 

 of one kind. They are amoeboid bodies, which when expanded 

 protrude a number of slender pseudopodia. When contracted, 

 they are ovoid or spherical. There is a single compact 

 nucleus, staining readily with methylene-blue. The cyto- 

 plasm is finely granular, and stains with eosin, but there are 



39 § 



