Sect. XXXIX. io. 2. GENERATION. 43 1 



tions from the new powers it has acquired, fo as to form a leaf 

 or lungs either at its fummit in the axilla of the parent leaf, or in 

 any other part of its length ; and alfo to form radicles below, 

 or from any amputated part. 



This new caudex gemmse is proved to commence its forma- 

 tion in feveral places at the fame time from the triple caudex of 

 the bud of a tree, which has been twice fuccefiively ingrafted, 

 which we have called a triple mule ; but as the new vegetable 

 cbnfiits in general of a combination of parts derived from one 

 parent, it much more accurately refembles that parent in its 

 form, growth, and difeafes, than the progeny from fexual or 

 feminal generation. The fame circumftances occur to the vege- 

 tables, which poffefs fhort and flat caudexes, which exift be- 

 tween the radicles and the root-leaves, as in the bulbs of tulips 

 and onions ; which might poflibly be ingrafted on each other like 

 the buds of different trees, and form curious mule bulbs. 



This lateral or folitary mode of propagation belongs likewife 

 to the polypus of our ditches, and to the hydra ftentorea, and 

 probably to many other infects. 



2. There is alfo a folitary internal mode of generation, which 

 occurs in the viviparous productions of the aphis, which are 

 known to proceed for eight or nine fuccefiive generations with- 

 out the congrefs of fexes ; but what is extraordinary, a con- 

 grefs of fexes appears to be necelTary in their production of an 

 oviparous progeny in the autumn for the prefervation of the fpe- 

 cies during winter •, whence it would feem, that folitary genera- 

 tion always produces a viviparous offspring. For the more par- 

 ticular hiftory of this wonderful and important infect fee Phyt- 

 ologia, Sect. IX. and XIV. To which may be added, that a 

 fimilar internal folitary mode of reproduction probably obtains 

 in the tenia, or tape-worm, of the inteftines, which afflicts va- 

 riety of animals, and of the aciinea, or fea-anemone, and of the 

 volvox, as defcribed in the Syftema Naturx of L'mneus. 



The eflential difference between the folitary lateral generation 

 and the folitary internal generation feems to confift in this ; 

 that in the former there are many glands, which fecrete or pro- 

 duce the fibrils with formative appetencies ; and many other 

 glands, which fecrete or produce the molecules with formative 

 aptitudes or propenfities ; and thatthefe numerous fecieiions are 

 mixed together and combine in one large receptacle beneath the 

 cuticle of trees, and of fbme infe£h, and there combining gener- 

 ate the organized particles, which conftitute the rudiment ot 

 the nevr cmbryon, producing many of the eflential parts oi it at 

 the fame time ; whereas in the latter, there probably exifts but 

 inc fe't of glands, which fecrete the fibril with formative appe- 

 tencies ; 



