INTRODUCTION. 47 
Of the additions which have been gradually en- 
grafted upon the original poem, it is not difficult to 
trace the origin and progress. 
First. Villa Nova had introduced many verses of 
4 similar nature into his commentary, not as parts of 
the poem, but professedly from other quarters, and 
which he carefully distinguished by such prefatory 
Words as, ut dicunt, juxta illud metricum, or undé 
versus isti communes. These lines, to the number 
of near forty, found their way early into the text, 
and became part of the usual copies, the edilio 
recepla, 
SECONDLY. The next storehouse for supplying 
additions was the poem-of Macer, from which much 
of the original had been taken. 
THIRDLY. Besides these, many floating verses, 
Some written as marginal notes, were occasionally 
absorbed and embodied, and other were purposely 
added by monks and transcribers. 
FouRTuLy. At length it was completely altered 
and reformed, in substance and method, fully to 
meet the ideas of the learned. Every subject 
which was deficient was supplied, those parts which 
Were too short were extended, and it was trans- 
formed into a complete compendium of the whole 
art of medicine. 
Since near two hundred years had elapsed between 
