I 



RESEARCH ON THE DIGESTIVE SYSTEM OF THE SCHIZOPODA 67 



a free pièce running above the folds br,. c. ierm. The paired diverticula are directed 

 forwards; in this species they are glandular. P,l^ indicates tlie position of the under 

 terminal portions of the latéral pièces S, . they penetrate into the intestine for a 

 considérable distance as fine blade-like chitinous plates. ;i; is a small eminence in 

 the posterior portion of the cavity. 2/3 in, X 3. 



FIG. 42. Transverse section through the anterior portion of the pyloric cham- 

 ber. The terminal upper portions of the latéral plates carry long spines 5i . The 

 folds br„ which connect the lower portions of the latéral plates Si with the folds 

 S^i of the pyloric chamber in this animal hâve a very thick cuticle on their upper 

 surface cl. The terminal free portion of the longitudinal ridge c. terni, lies upon the 

 folds br^ as a free pièce The superior médian pièce p. s m. is represented by a 

 pair of chitinous eminences bearing hairs directed downwards. The matrix of the 

 chitinous pièces is constituted of small cells with large nuclei closely packed to- 

 gether. D, X '• 



Histology. 



FiG. 43 to 51. 



FIG. 43. Vertical section through a bundie of muscle fibres undergoing trans- 

 formation into chitinous substance, m. indicates the région which is still muscular. 

 A dénotes the région of the atrophy ; the transverse striations are gradually dis- 

 appearing. Their terminal portions vvhere they are attached to the external cuticle 

 cl hâve been transformed into tendons t. d. It will be noticed that in the région 

 where the atrophy is taking place, whilst the transverse striations are disappearing, 

 the longitudinal ones are becoming accentuated. The muscle sheath or myosarc m se. 

 contains several large nuclei. 1/12 Leitz X i- 



FIG. 44. Section through the centre of one of the spherical bodies composing 

 the salivary gland. It is formed of a number of cone-shaped cells whose summits 

 almost meet in the centre, leaving only a small space from which the secreted 

 matter is carried ofî by a small canal. A number of vacuoles vc are seen in each 

 cell which in the living cell contain the secreted ferments The spherical bodies 

 are siirrounded by a serous membrane Ly. 1/12 Leitz, X 3. 



FIG. 45. Vertical section through one of the ventral tubes of Macromysis. The 

 tvvo kinds of cells are seen : (i) the ordinary secreting gland cells c. g. (2) the 

 elongated cells of the glandular ridge gl y. The ordinary secreting cells c. g. are of 

 différent sizes ; the larger ones contain vacuoles filled with granular secreted matter vc. 

 In the elongated cells of the glandular ridge a considérable portion of the proto- 

 plasm has been transformed, only the cell membranes remain, attached to a striated 

 plateau above. The nuclei n, are seen to be more elongated than the nuclei of 

 the ordinary secreting cells n. In the former case they lie close to the région of 



