Might not, by parity of inference, the milt of fishes, such as the herring, mackerel, etc., be a useful food in cases of consumption, both from the iodine necessarily existing in it, and also from its doubtless nutritive nature?
We are told that the cells of _Hylæus_, or _Prosopis_, and of _Ceratina_ are supplied with a semifluid honey. It is very doubtful if _Hylæus_ collects its own store, but that _Ceratina_ does, I have the authority of an exact observer (Mr. Thwaites) to verify it, for he has caught this insect with pollen on its posterior legs, which the long hair covering the tibia is intended for. What may be the nature of this semifluid honey? It is questionable if the larva could be nurtured upon honey alone without the admixture of pollen, thus contradicting analogies presumable from ample verification in nature’s processes. How, too, does it become semifluid? It is the property of honey, at a certain temperature, to be very fluid, and this is doubtless the temperature that prevails within the receptacle of the larva during the time of the operations of the bees.
Its semifluid consistency could then apparently be produced only by some more solid admixture, which, if not of pollen, of what can it be? This, even in small quantities, might, upon the bursting of its vesicles, have the power of thickening the fluent honey to the necessary consistency.
But a bee without polliniferous organs cannot collect pollen, and the instance of the hive bee, which collects honey in superabundance, feeding its larva with the bee-bread, must inevitably lead to the conclusion that the larvæ of bees require more than honey for their sustenance. Nature is not usually wantonly wasteful of its resources, and if honey sufficed for the nurture of the grub, so much pollen would not be abstracted from its legitimate purpose, nor would bees have this double trouble given to them. By the admixture of pollen the honey has energetic power infused into it by the spermatozoa which that contains. But it must necessarily be collected, for I never observed, nor have I seen recorded, any instance of the pollen being eaten on the flower and regurgitated into the cell in combination with the imbibed honey.