ABUNDANCE OF HYPOTHETICAL STAGES. 149 



are many. The embryologist does not seem to know 

 so much about the history of animals as he did 

 twenty years ago. In reality the reverse of this is 

 the truth, for these twenty years have seen a con- 

 tinual advance. While they have disproved many of 

 the old views, they have taught the student to be 

 cautious in founding conclusions on insufficient data. 

 In the very infancy of the subject, Haeckel boldly 

 traced the complete history of man from the simple 

 protozoan to his present condition. Without hesi- 

 tation he laid down the complete genealogy of man 

 from evidence found in his development, with no 

 attempt to get help from other sources. And in- 

 asmuch as embryology was in a very crude con- 

 dition at that time, we are not surprised to find 

 that this genealogy contained more errors than 

 truths. He divided man's history since the ap- 

 pearance of life into twenty-one stages, which he 

 thought were indicated by stages in his develop- 

 ment. It is needless here to enumerate these 

 stages, for little by little has it become evident that 

 most of them were guesses, or at least founded on 

 very insufficient data. Of these twenty-one stages, 

 more than half have been proved to be wrong, and 

 in regard to some of the others it is questionable. 

 This attempt of Haeckel, made with such boldness 

 as almost to inspire belief, is thus a failure. Nor has 

 Haeckel been alone in this attempt, for others have 

 essayed a like task. Darwin, with all his caution, 

 was led in his " Descent of Man " to trace out his 

 history, and he came no nearer the truth than did 

 Haeckel. But to-day the wiser naturalists do not 



