944 PROFESSOR W. C. M'INTOSH AND MR E. E. PRINCE ON 



Fig. 2. Horizontal section through the branchial arches of the same form, April 20, 1886. The 



branchial arches are indicated by the figures (Roman) : bbr, basibranchial ; infp, 



inferior pharyngeals ; bp, branchial papillae in section, . . . x 52 



Fig. 3. Transverse vertical section through the abdominal region of the advanced larval Anar- 



rhiekas, the hind-gut being severed just in front of the urinary vesicle, June 20, 1886, . x 55 

 Fig. 4. Similar section behind the foregoing, the termination of the hind-gut and the urinary 



vesicle being cut, May 1, 1886 : //, remains of longitudinal ligament, . . x 55 



Fig. 5. Similar section through the urinary vesicle and anus (a more advanced stage), June 20, 



1886, ........... x 97 



Fig. 6. Section posterior to the former through the urinary vesicle and its aperture in a post-larval 



form of the same date, . . . . . . . . x 97 



Fig. 7. Section (transverse vertical) through the rectum and urinary vesicle in front of the previous 



sections, May 1, 1886, . . . . . . . . x 55 



Plate XXVI. 



Fig. 1. Intestine of the larval Anarrliiclias, showing the circulation from the left side, February 



1886, ........... x 40 



Fig. 2. Similar view from the same form, seen from the right side, February 20, 1886, . . x 24 



Fig. 3. Transverse vertical section through the kidney of the same form at an advanced stage, June 



20, 1886, . . . . x 230 



Fig. 4. Transverse vertical section through the glomerulus in the same species, March 1, 



1886, .......... Highly magnified 



Fig. 5. Transverse section of the notochord of a salmon of the first day, showing nuclei and noto- 



chordal investments, ........ Highly magnified 



Plate XXVII. 



Fig. 1. Young Anarrliiclias lupus reared in the St Andrews laboratory, May 14, 1886, . x about 12 



Fig. 2. Circulation in the tail of the larval Anarrliiclias, March 13, 1886, . . . x 25 



Fig. 3. Caudal region of the advanced larval Anarrliiclias, showing the constrictions of the noto- 

 chord opposite the attachment of the neural and haemal arches, May 4, 1886, . . x 24 

 Fig. 4. Transverse section of the alimentary canal (stomachal region) of the advanced larval Anar- 

 rliiclias, June 20, 1886, . . . . . . . x 150 



Fig. 5. Transverse section of the oesophageal region of the alimentary canal, with the anterior end 



of the heart below, March 29, 1886, . . . . . . x 150 



Fig. 6. Transverse section of the same region of the canal, January 16, 1886, . . . x about 60 



Plate XXVIII. 



Fig. 1. Aboral termination of notochord and caudal circulation ' in the larval salmon (Salmo salar), 



1 day old, .......... Magnified 



Fig. 2. Lateral view of the circulation in the region over the ventral fin in a larval salmon of the 



same age, .......... Magnified 



Fig. 3. Capillaries in the region of the fatty fin (of the larva of the same species) in course of 



development, .......... Magnified 



Fig. 4. Ovum of the haddock (Gadus wglefinus), 5th hour; the two blastomeres are of unequal 



size, . . . . . . . . . . x 60 



Fig. 5. Ovum of the ling (Molva vulgaris), 4th day after fertilisation ; blastopore much reduced ; 



embryonic thickening very marked, ....... x 50* 



* This figure was drawn by Mr Prince. 



