SECT. XXXIX. 6. 5. GENERATION. 4 1 1 



of its fecretion ; and that fuch duplicature of limbs was pro- 

 duced by accretion of new parts, in confequence of propenfi- 

 ties, or animal appetencies, thus acquired from the male parent. 



For inftance, I can conceive, if a turkey-cock {hould behold a 

 rabbit, or a frog, at the time of procreation, that it might hap- 

 pen, that a forcible or even a pleafurable idea of the form of a 

 quadruped might fo occupy his imagination, as to caufe a tenden- 

 cy in the nafcent filament to refemble fuch a form, by the appo- 

 fition of a duplicature of limbs. Experiments on the production 

 of mules and monfters would be worthy the attention of a Spal- 

 lanzani, and might throw much light upon the fubjedr, which 

 at prefent muit be explained by conjedural analogies. 



The wonderful effect of imagination, both in the male and 

 female parent, is (hewn in the production of a kind of milk in 

 the crops both of the male and female pigeons after the birth of 

 their young, as obferved by Mr Hunter, and mentioned before. 

 To this fhould be added, that there are fome inftances of men 

 having had milk fecreted in their breads, and who have given 

 fuck to children, as recorded by Mr. BufFon. This effect 

 of imagination, of both the male and female parent, feems to 

 have been attended to in very early times ; Jacob is faid riot on- 

 ly to have placed rods of trees, in part dripped of their bark, fo 

 as to appear fpotted, but alfo to have placed fpotted lambs before 

 the flocks, at the time of their copulation. Genefis, chap. xxx. 

 verfe 40. 



5. In refpedt to the imagination of the mother, it is diffi- 

 cult to comprehend, how this can produce any alteration in the 

 fetus, except by affefting the nutriment laid up for its firft re- 

 ception, as defcribed in No. V. 2. of this feclion, or by affecl- 

 ing the nourifhment or oxygenation with which fhe fupplies it 

 afterwards. Perpetual anxiety may probably affect the fecre- 

 tion of the liquor amnii into the uterus, as it enfeebles the 

 whole fyftem ; and fudden fear is a frequent caufe of mifcar- 

 riage ; for fear, contrary to joy, decreafes for a time the adlion 

 of the extremities of the arterial fyftem ; hence fudden pale- 

 nefs fucceeds, and a fhrinking or contraction of the veflels of 

 the ikin, and other membranes. By this circumftance, I im- 

 agine, the terminations of the placental veflels are detached 

 from their adhefions, or infer tions, into the membrane of the 

 uterus ; and the death of the child fucceeds, and confequent 

 mifcarriage. 



Of this I recollect a remarkable inftance, which could be af- 

 cribed to no other caufe, and which I fhall therefore relate in 

 few words. A healthy young woman, about twenty years of 

 age, had been about five months pregnant, and going down in- 

 to 



