The Hairy Ammophila is one of the very rare exceptions among the Digger-wasps in the matter of nest-building; she gets hers ready in the early days of spring. Towards the end of March, if the season be mild, or at latest in the first fortnight of April, when the Crickets assume the adult form and laboriously cast the skin of infancy on the threshold of their homes, when the poet’s-narcissus puts forth its first flowers and the Bunting utters his long-drawn call from the top of the poplars in the fields, Ammophila hirsuta is at work digging a home for her grubs and victualling it, whereas the other Ammophilæ and the various Hunting Wasps in general postpone this labour until autumn, during September and October. This early nidification, preceding by six months the date adopted by the vast majority, at once suggests a few reflections. We wonder if the Ammophilæ whom we find occupied with their burrows in the first days of April are really insects of that year, that is to say, if these spring workers completed their metamorphosis and left their cocoons during the previous three months. The general rule is for the Digger to become a perfect insect, to quit her subterranean dwelling and to busy herself with her larvæ all in one season. Most of the Predatory Wasps leave the galleries where they lived as larvæ in the months of June and July and display their talents as miners and hunters in the following months of August, September and October. Does a similar law apply to the Hairy Ammophila? Does the same season witness the insect’s final transformation and its labours? It is very doubtful, for the Wasp occupied on the work of the burrow at the end of March would in that case have to complete her metamorphosis and to break out of her cocoon during the winter, or at latest in February. The severity of the climate at this period does not allow us to accept such a conclusion. It is not at a time when the bleak mistral howls for a fortnight without intermission and freezes the ground hard, it is not at a time when snowstorms follow close upon that icy blast, that the delicate transformations of the nymphosis are able to take place or the insect to dream of abandoning the shelter of its cocoon. It needs the warm moisture of the earth under the summer sun before it can leave its cell.