CHAPTER FOURTH. 



EXAMINATION OF THE INVESTIGATIONS OF FORMER OBSERVERS. 



e 



Review of Mutter's Observations. — It is with the greatest diffidence that I enter 

 upon this part of my subject. It seems the height of presumption, for one who has 

 scarcely any claim to recognition, to begin by criticizing so many statements of one 

 of the great masters of our science. Yet I hope to show, from Mtiller's own 

 figures, that the observations I have made upon the development of our Starfish, 

 though they do not agree with his earlier memoirs, yet coincide entirely with a few 

 figures which he has given on the last plate of his great memoirs on the embryology 

 of Starfishes ; and that it is only because Miiller neglected the earlier stages of 

 development, that he failed to arrive at the conclusions to which I have been led by 

 the above investigations. 1 trust that I have succeeded in describing the successive 

 stages in this development,, with clearness enough to enable me now to draw a com- 

 parison, which the reader may easily follow, with the last drawings made by Miiller, 

 and to show that, had he had the good fortune to see so complete a series as that 

 which I have traced, he would undoubtedly have entirely remodelled his former 

 views, with the same frankness which has characterized all his memoirs. No pre- 

 conceived theories, no observations, however careful, have ever been allowed by him 

 to interfere in the least with his subsequent observations. Hence the great diffi- 

 culty of following Miiller in his intricate discoveries ; each memoir modifying, 

 correcting, and sometimes entirely contradicting, the previous ones, so that we must, 

 as it were, begin his book at the end, in order rightly to understand his meaning. 

 Any one who has tried to follow the development of a single animal, so that 

 nothing should be wanting in the evidence of the successive stages, will easily 

 understand how later observations continually modify and explain what had pre- 

 viously been considered as well understood. 



Although Sars was the first who followed the development of an Echinoclerm 

 which, at first sight, did not seem to differ very materially from what was known 

 of the development of other Kadiates, yet Miiller was the first to trace the won- 

 derful changes of the young Echinoderms; his memoirs have been the basis of all 

 (54) ' 



