W. Bulloch 411 
metically sealed, the animalcules still made their presence known by a cloudi¬ 
ness which suffused the previously clear infusion. Animalcules still appeared 
in organic extracts deprived of air. In other experiments he first heated his 
flasks and having introduced his clear infusions and hermetically sealed the 
vessels heat was again applied for an hour. At last no infusoria could be found 
in the fluid even examined with the magnifier. If perchance a crack occurred 
in the vessel animalcules appeared sooner or later. He thus concluded that 
infusions sufficiently heated and kept from contact with unheated air ex¬ 
hibited no evidence of spontaneous generation. These experiments were con¬ 
tinued on a large scale the results being published in the Opuscoli (1776). He 
confirmed the observation of de Saussure (1769) that most of the animalcules 
of infusions reproduce by a process of division and by ingenious experiments 
he followed Volvoxglobator through thirteen generations. “It must be noted,” 
he says, that there are appointed times for these minute animalcules to 
originate and be destroyed as with other creatures that multiply to excess. 
Nature has with the wisest provision destined that when one species begins 
to be excessively numerous it is reduced either from the greater number of 
the animals perishing from disease or a violent death by the voracity of other 
animalcules for it is a perpetual and inviolable law with numberless animals 
that one lives upon another and mutual destruction preserves each species.” 
Our portrait of Spallanzani is a copy from the original which was drawn 
and engraved by C. Rampoldi and appears in the edition of his collected 
works. It has been redrawn and lithographed several times and appears 
with an added coat and stock in Pavesi’s book. There is also a picture of 
Spallanzani in clerical dress in Salimbeni’s book. His bust in terra cotta, 
by Barberini, graces one of the rooms in the Physiological Institute in 
Modena. 
BIOGRAPHICAL NOTICES OF SPALLANZANI. 
Alibert, J. L. tfloge historique de Lazare Spallanzani. Mem. de la Soc. med. £ emulation 
1800. Annee m. p. 1. 
Pavesi, P. U Abbate Spallanzani a Pavia. Milano, 1901. 
Pozzetti, P. Elogio di Lazzaro Spallanzani. Parma, 1800. 
Salimbeni, L. VAbbate Lazzaro Spallanzani. Modena, 1879. 
Senebier, J. Notice historique sur la vie et les ecrits de L. Spallanzani, in Memoires sur 
la respiration par Lazare Spallanzani. Geneve, An. xi (1803). 
Tipaldo. Biografia degli Italiani illustri. Venezia, 1834-1845. 
Tourdes, J. Notices sur la vie litt6raire de Spallanzani in Tourdes’ French translation of 
Deifenomeni della Circolazione. Par., An. vm. also English transl. Lond., 1801. 
SPALLANZANI’S PRINCIPAL WORKS. 
1. Saggio di osservazioni microscopiche concernenti il sistema della generazione di Signori di 
Needham e Buff on 1765. Reprinted in Nuova raccolta d' opuscoli etc. Venezia 1767 
xv, 208-323. ' ’ ’ 
2. Prodromo di un opera da imprimersi sopra riproduzioni animali. Modena, 1768, 102 pp. 
3. Dell azione del cuore ne' vasi sanguigni nuove osservazioni. Modena, 1768, 71 pp 
