FINGER-PRINTS—THEIR EVOLUTION AND SIGNIFICANCE. 205 
Their Evolution—Like the majority of mammals, man is 
provided with five digits, ie, he is pentadactylous; but at 
first sight it appears asif the hands and feet of man presented 
no trace of the elevated “pads” which are such charac- 
teristic features of the tips of the toes and soles of the feet 
in mammals. A closer examination, however, will show that 
without exception a “pattern” area occurs in each of the 
localities which correspond to the “pads” of an animal’s 
foot. Now, while these “pattern” areas are always 
somewhat elevated, they do not attain the proportions of 
“pads” separated from each other by deep grooves, because 
the purposes which are served by the hand and foot of man 
are attained by the sacrifice of resilient elastic pads, and the 
adoption of length and breadth associated with comparative 
flatness of their general surface. An examination of the 
“pads” in the hand and foot of a very young fcetus 
reveals the fact that they are projecting, somewhat 
cylindrical or conical, elevations, but as growth advances, the 
Shape of each “pad” undergoes more or less extensive 
modification. In consequence of this pointed, cylindrical, or 
almost conical character of the “pads,” it follows as a 
matter of course that the papillary ridges of the true skin 
assume the form of circles surrounding a central point, and 
that the gradual increase in the size of the “ pads” permits 
the production of additional circles until the “pad” is 
completely formed. Hence it is that the development of a 
“pad,” which begins with the elevation of a point and whose 
area of extension is restricted, determines the presence of a 
“pattern,” the primary design of which is a series of 
concentric circles. Nevertheless the designs undergo an 
infinite variety of modifications, due simply to the equally 
great variation in the rate of growth of the “pad” area, as 
well as to the variability of the extent of its surface area. 
The careful examination of large numbers of “ patterns ” 
has led me to regard the concentric circles as the primary 
design out of which “whorls,” “ loops,” and “tents” are 
readily evolved according to the rate of growth and the area 
available, Moreover, “ whorls” are more nearly allied to 
the primary circle designs than loops and tents; and while 
as yet no racial character has been associated with either of 
VOL. I. 16 
