The comparative embryologist of our day is inclined to be a hyper-theorist, and so it seems that some have not remained content with either of the above accounts; to them, apparently, the production of the large and complex head of the imago out of a single small anterior segment of the maggot requires a more recondite explanation, and must be brought into harmony with analogous facts. To this end some degree of linked support is found by the investigations of microscopic anatomy, and it has been conjectured that not one or two head segments, but five are lying blended and embryonically hidden in the larvæ, all ready to bud forth. However, for fear of wearying too much with the theories of advanced erudite scientists, the following _jeu d'esprit_ is presented, instead of a more elaborate and sober attempt, to lure the unscientific lay reader to an extreme hypothetical conception of the "essential unity" underlying the apparent diversities of Nature within that vast domain of the Kingdom of Fauna, which is obviously outside the later creation of a vertebrate Animalia. [Illustration: Fig. 5. Illustrating the debatable continuity of a 12-segmented structure throughout the metamorphosis. ] The futurist's dogmatic CREDO of creative progress, "For him who would meritoriously pass his histological examinations, and qualify as a Professor and Doctor of Science, above all it is necessary that he should acknowledge the unicellularity of the primæval OVUM (or egg), whence proceeds the seventeen-segmented boneless ANNELID (or worm), out of which there develops the quadrangular articulated crustacean INSTAR (or shell-encased aurelian), which metamorphosises into the winged IMAGO (the angelic? or diabolic? fly); in the contemplation of this knowledge alone is there supreme Darwinian Modernismal salvation and felicity." Amen. In view of the prosaic illustration of transmutation, figure 5 above, the futurist disciple will have to accept the seventeenness of segmentation by something like faith without sight. The quadrangularity of the crustacean stage is based upon the idea that the wings bud out from the two upper corners, whilst the legs develop from the lower corners of the transmuting instar. Perchance the reader will desire information about the use of this curious word "instar," which has not the honour of notice in Dr. Sir J. Murray's New English Dictionary. One might well feel proud of the opportunity of adding the smallest item to such a stupendous and monumental work, but I fear I am only qualified to venture a fair guess. Virgil, I believe, used this term in allusion to the legendary wooden horse of the Greeks at their siege of Troy. Some time less than one hundred years ago entomologists recognised that the words aurelian, chrysalis, and pupa were none of them an inherently fit term of general application to the stage of insect life to be indicated. After many attempts, this latest proposed substitute seems to be gaining favour.