430 PHILOSOPHICAL TRANSACTIONS. [aNNO 1740. 



unfolding and expansion of their vessels, by a slow and progressive insinuation 

 of fluids adapted to their diameters, until being stretched to the utmost bounds 

 allotted them by Providence at their formation, they reach their state of perfec- 

 tion, or, in other words, arrive at their full growth. — If this be granted, the 

 consequence must be, that all the members of a perfect animal exist really in 

 every animalcule of the semen animale masculinum, and all the parts of a per- 

 fect plant in every little grain of the farina plantarum, however minute either of 

 them may be. 



According to this theory, it is supposed by some, that, in animals, the semen 

 of the male being received into the matrix of the female, some of the animal- 

 cules it contains in such abundance, find an entrance into the ovaria, and lodge 

 themselves in some of the ova placed there by Providence as a proper nidus for 

 them. An ovum, becoming thus inhabited by an animalcule, gets loosened in 

 due time from its ovarium, and passes into the matrix through one of the 

 Fallopian tubes. The veins and arteries that fastened it to the ovary, and were 

 broken when it dropped from thence, unite with the vessels it finds here, and 

 compose the placenta : the coats of the ovum, being swelled and dilated by the 

 juices of the matrix, form the chorion and the amnion, integuments needful to 

 the preservation of the little animal, which, receiving continually a kindly 

 nourishment from the same juices, gradually stretches and enlarges its dimen- 

 sions, becoming then quickly visible with all the parts peculiar to its species, 

 and is called a foetus. 



In plants, say they, which are incapable of removing from place to place, as 

 animals can, it was requisite a repository for their farina should be near at hand 

 to prevent its being lost ; and accordingly we find, that almost every flower, 

 producing a farina, has likewise in itself a proper ovary for its reception ; where 

 the ova thereby impregnated, are expanded by the juices of the parent plant, to 

 a certain form and bulk, and then, becoming what are called ripe seeds, they 

 fall to the earth, which is a natural matrix for them. 



According to the above supposition, a ripe seed, falling to the earth, is in the 

 condition of the ovum of an animal getting loose from its ovary, and dropping 

 into the uterus : and, to go on with the analogy, the juices of the earth swell 

 and extend the vessels of the seed, as the juices of the uterus do those of the 

 ovum, till the seminal leaves unfold, and perform the office of a placenta to the 

 infant included plant ; which, imbibing suitable and sufficient moisture, gra- 

 dually extends its parts, fixes its own root, shoots above the ground, and may 

 be said to be born. 



Others disapprove of this hypothesis, and insist that no animalcule can 

 possibly enter the ovum animale, nor any particle of the farina get into the 



