KEEATOSES. 



361 



liorny lamella?. The hairs upon the affected patch are thin and 

 caducous ; this points to a disturbance in their nutrition, due to 

 the cornification of the hair-sac. The process extends as a rule, 

 deep into the fundus of the sac; the hair-bulb proper alone 

 remaining unaflPected. Fig. 114 represents a vertical section 

 through an ichthyotic scale, and sllo^ys its connexion with the 

 underlying skin. The specimen was taken from a calf affected 

 with congenital ichthyosis ; it is preserved in the Physiological 

 Institute at Breslau,* and is especially fitted to shed light on the 

 relation of ichthvosis to the hair-sacs. 



41 . n 



Fig. lU. 



^ 







^'K^os 



^(f 



Ichthyotic scale ; Tcrtical section. Taken from a calf affected 

 with ichthyosis, s^j- 



§ 305. With Ichthyosis we may associate cutaneous horns 

 {cornu humanum) as circumscribed varieties of keratosis. A 

 monster of this description (9 inches in length) is preserved in 

 the collection of the Pathological Institute at Bonn. As the 

 tigure (fig. 115) shows, it is a rounded prism, longitudinally 

 grooved, and spirally twisted like a ram's horn. Most cutaneous 

 horns, though neither as long nor as thick as this one, present 



* Cf. Harpeck, description of the skin of a calf born with Ichthyosis 

 cornea. Beichert u. Dulois-R-AjmoiuVs Archiv. Jahrgang 1862. Heft iii. 

 T). 393. 



