io 4 BIOLOGICAL PHYSICS 



treatment may be applied to them, on somewhat definite 

 and scientific lines, instead of on the rather empirical and 

 haphazard principles which have hitherto been relied 

 upon in the absence of definite anatomical and physiological 

 bases; for instance, we may perceive common, or kindred, 

 causes at work along definite lines, anatomical and 

 histological, in the production of a common cold, a coryza, 

 or an influenza, the running at the eyes and nose, the 

 headache, the nasal and pharyngeal catarrh, with the early 

 associated local and general symptoms, following each 



FIG. 36. THE LOWER OR CARTILAGINOUS PART OF THE CRANIUM OF A 

 CHICK OF THE SIXTH DAY. (From Huxley.) 



i, i, chorda dorsalis; 2, the shaded portion here and forwards is the cartilage of the 

 base of the skull ; at 2, the occipital part ; at 3, the prolongations of cartilage into 

 the anterior part of the skull called trabeculce cranii ; 4, the pituitary space ; 

 5, parts of the labyrinth. 



other, or occurring simultaneously, according to which part 

 of the involved mucosa, Schneiderian, or pharyngeal, is 

 first invaded by the materies morbi, thus pointing the way 

 to secure the amelioration, or cure, of these oft-recurring 

 and sometimes dangerous affections. A common cold is, of 

 course, most frequently due to mere mechanical disturbance 

 of the process of the distribution, or circulation, of the 

 cerebro-spinal fluid, and disappears spontaneously and 

 without the necessity for medical intervention by the 

 unassisted operation of the regulative influences inherent 

 in, and the automatic health-preserving forces possessed 

 by, all living organisms. 



