34 Additional Notes. 



intercourse. One extremity of the tEEiiia, is said by Linneus to grow 

 old, whilst at the other end new ones are generated proceeding to 

 infinity like the roots of grass. The vplvox globator is transparent, 

 and carries within itself children and grandchildren to the fifth 

 generation like the aphides; so that the ta^nia produces children and 

 grandchildren longitudinally in a chain-like series, and the volvox 

 propagates an offspring included within itself to the fifth generation; 

 Syst. Nat. 



Many microscopic animals, and some larger ones, as the hydra or 

 polypus, are propagated by splitting or dividing; and some still 

 larger animals, as oysters, and perhaps eels, have not yet acquired 

 sexual organs, but produce a paternal progeny, which requires no 

 mother to supply it with a nidus, or with nutriment and oxygenation; 

 and, therefore, very accurately resemble the production of the buds 

 of trees, and the wires of some herbaceous plants, as of knot-grass 

 and of strawberriesj and the bulbs of other plants, as of onions and 

 potatoes; which is further treated of in Phytologia, Sect. VII. 



The manner in which I suspect the solitary reproduction of the buds 

 of trees to be effected, may also be applied to the solitary generation 

 of the insects mentioned above, and probably of many others, perhaps 

 of all the microscopic ones. It should be previously observed, that 

 many insects are hermaphrodite, possessing both male and female 

 organs of reproduction, as shell-snails and dew-worms; but that these 

 are seen reciprocally to copulate with each other, and are believed not 

 to be able to impregnate themselves; which belongs, therefore, to 

 sexual generation, and not to the solitary reproduction of which I am 

 now speajdng. 



As in the chemical production of any new combination of matter, 

 two kinds of particles appear to be necessary; one of which must 

 possess the power of attraction, and the other the aptitude to be 

 attracted, as a magnet and a piece of iron ; so in vegetable or animal 

 combinations, whether for the purpose of nutrition or for reproduc- 

 tion, there must exist also two kinds of organic matter; one possessing 

 the appetency to unite, and the other the propensity to be united; 

 (see Zoonomia, octavo edition, Sect. XXXIX. 8.) Hence in the 

 generation of the buds of trees, there are probably two kinds of 



