History of the human body / by Harris Hawthorne Wilder.

  • Harris Hawthorne Wilder
Date:
1909
Catalogue details

Licence: Public Domain Mark

Credit: History of the human body / by Harris Hawthorne Wilder. Source: Wellcome Collection.

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    apparent to the early morphologists, one of the greatest of whom thus expressed his feelings while gradually tracing back from the adult condition the developmental history of the skull of the common fowl: “ Whilst at work I seemed to myself to have been endeavoring to decipher a palimpsest, and not one erased and written upon again just once, but five or six times over. Having erased, as it were, the characters of the culminating type,—that of the gaudy Indian bird,—I seemed to be among the sombre Grouse; and then, towards the end of incubation, the characters of the Sand-grouse and Hemipod stood out before me. Rubbing these away, in my downward work, the form of the Tinamou looked me in the face; then the aberrant Ostrich seemed to be described in large archaic characters; a little while, and these faded into what could just be read off as pertaining to the sea-turtle; whilst, underlying the whole, the Fish in its simplest Myxinoicl form could be traced in morphological hieroglyphics.” * In following out the historical development of the different systems, as outlined in the ensuing chapters, both embryonic and phylogenetic records have been drawn upon as the primary sources from which this history may be deduced, and the conclusions which have the corroboration of both may be naturally considered the most trustworthy ones. Each of these two records has its advantages and its disadvantages; in the former the stages are continuous, although the early ones are obscure, and all parts of the record are apt to be overlaid and mystified by csenogenetic changes; in the latter the record is far more fragmentary and its stages are discontinuous, but the facts are usually plainer and more easily read. An adult lower animal which represents a phylogenetic stage in the history of a higher shows the parts in full physiological efficiency, while in an embryonic stage the organs are at the best not wholly functional, and often render it difficult to imagine an adult animal with the same relationship of parts; on the other hand, in places where a long historic period has no known living or * W. K. Parker, in Trans. Roy. Philos. Soc , 1869, pp. 803-804.