292 Fi'oofs of Erolution. 



in origin, while Homology relates to those parts or organs 

 which, however dissimilar in office, were derived from one 

 and the same part, modified and readjusted by use. For 

 example, the wing of a bird and the wing of a butterfly are 

 analogous, since they are both used for flying; but they 

 are not homologous, for they had not a common origin. But 

 the wing of a bird, the fore-paw of a reptile or mammal, and 

 the arm of a man, are homologous, since they have the same 

 general structure, modified for different uses. Analogous 

 parts look alike, but are not alike ; while homologous parts 

 may have little or no resemblance, but are in fact the same 

 l^arts in disguise. 



Morphology, or the scieiice which describes the ideal 

 forms or parts of organs, — the so-called structural "types " 

 in living organisms, — runs throughout the entire animal 

 and vegetable kingdoms. The structural evolution of one 

 mammal is a type of the structural development of all. We 

 will therefore select the horse, as at once the most beauti- 

 ivl and useful, needing only the gift of language to make 

 him human. The beautiful form, color, size and structure 

 of this animal were not fashioned at once, but have come to 

 their present perfection through small and gradual changes 

 extending back through vast periods of time. It has taken 

 Natui-e ages and ages to make a horse, and she isn't done 

 with him yet or he wouldn't balk and shy. The stock- 

 breeders have joined hands with Nature and are rapidly 

 improving his beauty, speed, and strength, while heredity 

 is silently keeping the score. 



From Geological discoveries we know that the horse 

 came from a five-toed ancestor. In Europe, India and Amer- 

 ica he has been traced as far back as the early Eocene 

 period, where he appeared no larger than a common fox. 

 He then had three toes behind and foiir in front, with the 

 rudiment of a fifth. Later on, we find him increased to 

 the size of a sheejD, but minus the rudimentary toe. The 

 next advance was to a three-toed animal all around, about 

 the size of a yearling colt, with the rudiment of a fourth 

 toe on each foot. This stage of his development was fol- 

 lowed by a shortening up of the side toes, while the middle 

 toe grew broader and stronger. Finally, in the Quarternary 

 period, we have the modern horse as we see him to-day, — 

 the side-splints yet remaining, as rudiments, to tell of his 

 long line of descent. 



