216 PROFESSOR TURNER'S ACCOUNT OF THE GREAT FINNER WHALE 



clefts. Under higher powers of the microscope, the intermediate substance 

 was seen to consist of flattened cells, epithelial in character (fig. 24), and the 

 black pigmentary layer was due to a special accumulation of pigmentary 

 granules in the deepest cells of this substance. This layer may be considered 

 therefore as comparable to the Rete Malpighii of the human cuticle. 



The intermediate substance was intimately united to the laminae formed by 

 the cleavage of each plate at its base ; so close indeed was this union that it was 

 impossible to separate them from each other without injury to the latter. It 

 not unfrequently happened, in tearing away the substance from between the 

 plates, that a portion of the cortical layer of the adjacent part of the plate 

 peeled off along with it. A distinct horizontal lamination was seen on the 

 surface of vertical sections made through the intermediate substance. 



In my further researches into the structure of the baleen, I have derived 

 considerable assistance from the examination which I made of the baleen of a 

 recently killed, lesser Pike whale, B. rostrata, about 18 feet long, which was 

 captured at Burntisland in September last. In this animal the plates were for 

 the most part white, or yellowish- white, but, when quite fresh, a distinct pink 

 or rosy colour was seen, more especially in that part of the blade which lay 

 within and next to the intermediate substance. Some days after death the 

 pink or rosy colour became converted into purple. 



When a fresh blade was examined in a good light, the pink colour was 

 found to be not on the surface, but within the substance of the plate, and 

 arranged in regular lines, which ran parallel to each other from the attached 

 border to the free border fringed with setae, and in many cases it extended even 

 into and along the latter. When a pocket lens was used in the examination, 

 the colour was seen to be due to a red fluid contained in the numerous tubes 

 which traversed the plate in its vertical diameter. Sometimes the fluid formed 

 an unbroken column of one, two, or three inches in length ; but at others the 

 column was much subdivided, and reminded one of the appearance presented 

 by a broken-up column of mercury in a barometer tube when out of repair. In 

 some of the tubes, more especially those situated near the outer and inner 

 edges of the plate, the red fluid was either absent, or extended only a short 

 distance down the tube. Many of these tubes appeared as if subdivided by 

 little septa passing across their canals, not unlike the arrangement one has 

 seen in the medullary part of a hair. When the baleen plate was cut across 

 transversely, and forcibly squeezed between the finger and thumb, the red 

 fluid oozed out of the divided tubes, and when collected on a glass slide was 

 examined microscopically. Under a high power numerous circular, disk-shaped, 

 non-nucleated corpuscles, which possessed the optical characters of blood cor- 

 puscles, were found in it (fig. 25), and along with these were three-sided pris- 

 matic crystals, probably the triple phosphate, and numerous actively moving 



