Growth in Length: Embryological Essays

Abstract

ALL zoologists will be grateful to Mrs. Assheton for the publication of these embryological essays found amongst the papers of her late husband. Whilst nominally dealing, as the title indicates, with “growth in length,” they are really a beautiful and clearly expressed summary of the early stages in development of the Vertebrate embryo, ranging through the whole series from the Elasmobranch to the Mammal. The facts are, of course, interpreted according to the late Dr. Assheton's views, with most of which we should be inclined to agree. The only point of criticism that seems to us worth raising is whether Dr. Assheton was justified in accepting on the evidence the statement that, the “segmentation cavity “in the segmenting eggs of Amphibia becomes incorporated in the gut. Brachet's work (which Dr. Assheton quoted) does not warrant such a conclusion; he found, indeed, that the wall dividing the gut from the segmentation cavity was often torn during growth, but that the rent healed up again. This temporary communication between the two cavities is therefore only one of the dislocations produced by unequal growth, and has no further significance.

Growth in Length: Embryological Essays.

By Richard Assheton. Pp. xi + 104. (Cambridge: At the University Press, 1916.) Price 2s. 6d. net.