Initiative in Evolution

by Walter Kidd

I have to thank one critic, Miss Inez Whipple, now Mrs. H. Wilder Harris, for her able if hostile criticism of two former books of mine which has been of use in this one; and Mr. R. E. Holding for good help extending over many years in the prepara­tion of the illustrations, and for many a good sugges­tion.

W.K.

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CONTENTS.

CHAPTER		PAGE
I.—	From Known to Unknown	[1]
II.—	Review of the Position	[8]
III.—	The Problems Presented	[22]
IV.—	Initial Variations and Total Experience	[30]
V.—	Method of Proof	[36]
VI.—	Evidence from Arrangement of Hair	[39]
VII.—	The Evolution of Patterns of Hair	[50]
VIII.—	Can Muscular Action change the Direction of Hair in the Individual?	[64]
IX.—	Habits and Hair of Ungulates	[74]
X.—	Habits and Hair of Ungulates	[86]
XI.—	Habits and Hair of Carnivores	[92]
XII.—	Habits and Hair of Carnivores	[98]
XIII.—	Habits and Hair of Primates	[103]
XIV.—	Miscellaneous Examples	[115]
XV.—	Experimental	[124]
XVI.—	First Summary	[140]
XVII.—	Varieties of Epidermis	[145]
XVIII.—	Arrangement of the Papillary Ridges	[157]
XIX.—	Flexures of the Palm and Sole	[170]
XX.—	The Evolution of a Bursa	[178]
XXI.—	The Plantar Arch	[192]
XXII.—	Muscles	[200]
XXIII.—	Innervation of the Human Skin	[218]
XXIV.—	The Building of Reflex Arcs	[231]
	Summary	[257]
	Index	[259]

LIST OF ILLUSTRATIONS.

FIG.		PAGE
1	Arrangement of hair on the forearm	[42]
2	Diagrams of hair-patterns	[51]
3, 4, 5	Neck of horse, showing muscles and tendons	[53], 54
6–19	Side of neck of various horses, showing varieties of hair-patterns	[56]–[62]
20–29	Illustrations of human eyebrows, showing muscular action and hair-direction	[70]–[73]
30	Front view of horse, showing pectoral pattern	[76]
31	Side view of horse showing hair-direction	[77]
32, 32a	Frontal region of horses, showing muscles and hair-pattern	[78]
33	Side view of horse, showing chief superficial muscles	[79]
34, 35	Side and back views of cow, showing hair-patterns on back	[88]
36	Lioness, showing direction of hair-streams on muzzle	[93]
37	Back of lion, showing hair-pattern	[95]
38–40	Gluteal region, foreleg and chest of domestic dog, showing hair-direction	[99], [101]
41	Arrangement of hair on back of lemur, chimpanzee and man	[105]
42	Idem chest	[109]
43	Giraffe, showing hair-patterns of neck	[116]
44	Giraffe in attitude of drinking or browsing off the ground	[117]
45	Bongo, showing hair-patterns of chest	[119]
46	Kiang. Side view showing inguinal and axillary patterns	[119]
47	Forefoot of llama, showing hair-direction	[120]
48	Two-toed sloth, showing action of gravity on hair	[123]
49	Domestic horse, fully harnessed	[128]
50	Side view of domestic horse, showing reversed hair due to harness	[129]
51–58	Necks of various horses, showing reversed hair due to collar	[132]–[135]
59	Right hand, drawing of papillary ridges, made from impressions	[158]
60	Right foot. Idem	[160]
61–70	Hands and feet of lower animals, showing papillary ridges	[161], [163]–[166], [168]
71	Flexures on palm of right hand. Drawing made from impression	[171]
72–79	Flexures on hands and feet of various lower animals	[172]–[175]
80	Drawing of flexures of sole of foot of man, young adult	[176]

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CHAPTER I.
FROM KNOWN TO UNKNOWN