Mr. Darwin, the eminent naturalist, says the Gardeners1 Chronicle, is continuing his experiments on the vitality of seeds, with a view to arrive at data as to the distribution of plants. Among the points involved in this interesting inquiry are - the length of time in which a seed will live in the intestines of a bird or other animal, and the circumstances under which it may be dropped in a distant place, and germinate: also, how long will seeds retain their vitality when floating in the currents of the sea? The last question is now under investigation with seeds collected on the coast of Norway, and at the Azores, whither they had been drifted by the Gulf-Stream. Another branch of the inquiry relates to the distribution of species of fish. Naturalists want to know, for instance, whether the eggs of salmon will retain their vitality sufficiently long to produce fish, when carried through varying temperatures to places wide apart. In one way, the question has been answered in the affirmative by the piscicultural experiments to which we have mere than once called attention. Dr. Davy has now solved it in another way.

He took impregnated ova of the char, from a stream falling into Windermere, and subjected them to temperatures varying from 70° to 98°. The result showed, that the older the eggs the better they resisted the heat: the youngest died in the first experiments. Another mode was sending ova packed in wet wool, inclosed in a tin box, from Ambleside to Penzance, and back again - more than a thousand miles - and with like results. And such being the case with the very delicate char, there is good reason to believe of the more hardy salmon species, that the strength of vitality of the impregnated ovum, or its power of resisting agencies unfavorable to its life, gradually increases with age, and the progress of total development.