a series of developments similar in all respects to that by which a single embryo is formed from each egg in other animals.  We have other Naticas in which the normal number is twelve, others again in which no less than sixteen individuals arise from one yolk.  But this process of segmentation, though in these animals it leads to such a multiplication of individuals, is exactly the same as that discovered by K.E. von Baer in the egg of the Frog, and described and figured by Professor Bischof in the egg of the Rabbit, the Dog, the Guinea-Pig, and the Deer, while other embryologists have traced the same process in Birds, Reptiles, and Fishes, as well as in a variety of Articulates, Mollusks, and Radiates.

Multiplication by division occurs also normally in adult animals that have completed their growth.  This is especially frequent among Worms; and strange to say, there are species in this Class which never lay eggs before they have already multiplied themselves by self-division.

Another mode of increase is that by budding, as in the Corals and many other Radiates.  The most common instance of budding we do not, however, generally associate with this mode of multiplication in the Animal Kingdom, because we are so little accustomed to compare and generalize upon phenomena that we do not see to be directly connected with one another.  I allude here to the budding of trees, which year after year enlarge by the addition of new individuals arising from buds.  I trust that the usual acceptation of the word individual, used in science simply to designate singleness of existence, will not obscure a correct appreciation of the true relation of buds to their parents and to the beings arising from them.  These buds have the same organic significance, whether they drop from the parent stock to become distinct individuals in the common acceptation of the term, or remain connected with the parent stock, as in Corals and in trees, thus forming growing communities of combined individuals.  Nor will it matter much in connection with the subject under discussion, whether these buds start from the surface of an animal or sprout in its interior, to be cast off in due time.  Neither is the inequality of buds, varying more or less among themselves, any sound reason for overlooking their essential identity of structure.  We have seen instances of this among Acalephs, and it is still more apparent among trees which produce simultaneously leaf and flower-buds, and even separate male and female flower-buds, as is the case with our Hazels, Oaks, etc.

It is not, however, my purpose here to describe the various modes of reproduction and multiplication among animals and plants, nor to discuss the merits of the different opinions respecting their numeric increase, according to which some persons hold that all types originated from a few primitive individuals, while others believe that the very numbers now in existence are part of the primitive plan, and essential to the