THE PHYSIOLOGY OF THE SENSE OF TOUCH 159 



accounting for their development on secondary pads where 

 they are needed in their measure, just as the corresponding 

 arches, loops, and whorls are on the primary pads. It would 

 seem that in reference to this particular matter. Miss Whipple 

 led astray from a useful physiological view of the patterns in 

 her earnest search for morphological consistency and homologies, 

 has read the series of patterns backwards. 



At this point there is apparently a divergence of paths, and 

 reconcilement of the two views does not seem possible. 



This digression into controversial matters is justified by the 

 fact that if the view here put forward as to the connection of 

 the patterns with the sense of touch be correct, and the opposing 

 theory that they are mechanical contrivances to prevent slipping 

 be incorrect, the whole field of the complex and varying patterns 

 on the hand and foot of man and the lower mammals is opened 

 up to a fruitful study. In this case, researches such as 

 those of Ch. Fere, on the functions of the human hand and 

 foot in connection with the patterns of the papillary ridges 

 are abmidantly justified. It may be useful here to refer to 

 some observations made by Schlaginhaufen, and summarised 

 in his paper * referred to before. He has examined the tactile 

 sensibihty of the human finger-tips in a way similar to that 

 of Weber. He applied the two points of a pair of compasses 

 at a fixed distance from one another to the finger-tips in different 

 directions, and came to the following conclusions ; 



(1) That they are distinguished better as two points when 

 their line of junction is at right angles to the direction of the 

 ridges, than when this is parallel with them or hes on them. Thus 

 the two points, c and d, are better distinguished than c and h. 



(2) That they are distinguished better when they lie on the 

 pattern in such a manner that their line of junction, cd, 

 representing part of a large curve, chad, is at right angles to 

 the direction of the ridges, than when they are so placed that 

 their fine of junction is along a rectilinear portion of ridge. 



(3) That they are distinguished better when they lie so on 

 the ridges that their hne of junction joins two points of the 



« See p. 143. 



