154 DR. WALTER KiDD ON THE [June 17, 



the neck from this whorl is met by a forw^ard stream, and a crest 

 is produced by the two opjDosing streams. The forward stream 

 from the trunk is a feathering which starts from a whorl situated 

 about the middle of the dorsal region. In this view of the 

 median plane there are seen three whorls, two crests, and at each 

 of the latter two opposing streams of hair. 



It seems hardly possible that these ari-angemeuts of hair and 

 reversed slope in two sej^arate areas can be connected with any 

 other cause than muscular action, especially that of the pan- 

 niculus carnosus, whose fibres here lie nearly in the long axis of 

 the ti'unk with a slightly downward direction. It corresponds 

 with the arrangements found on the back of other forms, such as 

 the Lion, certain Antelopes, Bovidfe ; and some with longitudinal 

 and central crests or manes, as in Connochcetes and Oreas canna. 



Whorls and foi-waixl featherings in the spinal region are not 

 very common, and would appeal- to be detei-mined by the activity 

 of the panniculus carnosus employed in defence of the animal 

 against flies and vai'ious insects. This function is also subserved 

 by the tail, so that an animal possessing an efiicient tail, and 

 presenting, in a spinal whorl and feathering, the evidence of a 

 very active " fly-shaker," as it is popularly called, is well adapted 

 for existing in areas where flies abound. It is worth noting that 

 such animals as Cervidse, Ovidte, Capra, Gazelles, with few excep- 

 tions, present neither efficient tails nor this pai-ticulai- evidence 

 in the hair of a very active " fly- shaker," but that many of the 

 larger Antelopes, true Oxen, and Girafies present both efficient 

 tails and evidence of activity of this supei-ficial muscle in whorls, 

 featherings, and longitudinal crests or manes. Some of the most 

 marked instances of spinal Avhoi-ls and manes have been studied, 

 and measurements taken fi-om the root of the tail to the tip, and 

 from the same point to the situation of the spinal whorl. These 

 measurements of 17 species and 29 specimens are given, by which 

 it is shown that animals which possess well- developed manes and 

 ijpinal whorls and featherings also possess efficient tails, though 

 the distance between the root and tip of tail, and root of tail and 

 whorl or end of mane, in some forms, does not cori-espond closely, 

 which one would haixlly expect. 



The species examined and the measurements were as follows . — 



-nt . , From root of tail 



i rom root to . • i i i 



,. n , ■■, to spinal whorl 



tip 01 tail. J n 



^ or end of mane. 



Connochcetes gnu 32 inches. 29 inches. 



,, taurinus 24 ,, 28 ,, 



Orya; ^«;se?Za (2 specimens) -j' q-. " -,, " 



,, 6eisa (2 specimens) \ ^f. " i oi " 



Hippotragus niger... 20 ,, 38 „ 



,, equinus 25 „ 36 ,, 



Oryxheatriso 17 „ 10 „ 



