92 THE EEPOET OF THE Xo. 36 



For 1,600 years after the time of Pliny the seiejitifie world slept, and, as a 

 consequence, at the beginning of the 17th century the work on galls had been 

 advanced very little beyond where the ancient naturalists had left it. During the 

 time elapsed, while no apiDreciable progress was made, several writers had in- 

 cidentally mentioned galls. Magnus (1193-1380), and Konrad ^■on Megenberg 

 (1309-1337), in particular, have referred to them in their general discussion of 

 the oaks. The latter author introduced the term "oak-apple" as a synonym for 

 the older name " gall-nut." Mattioli and Lonicer, about the year 1600, wrote on 

 the subject, and, in imitation uf the early physicians, recommended the gall 

 extracts as a panacea for many ailments. Galls, acorns, and mistletoe were re- 

 garded as three varieties of oak fruit by these authors. Their belief in the oracular 

 powers of galls has already been considered. 



These desultory references to galls, however, do not indicate any special 

 interest, and we may say that the subject had never been approached in a serious 

 scientific manner until its importance attracted the attention of tho Italian 

 physiologist, Marcello Malpighi (1628-1694). This investigator was the out- 

 standing figure of his age in medical science. He was physician to Innocent XII, 

 and professor of medicine at Bologna, and afterwards at Messina. In his methods, 

 he isolated himself entirely from the dogma of tradition, and based his con- 

 elusions upon his own observations. In his research work, he investigated the 

 anatomy of the brain and lungs, and made a beginning in embryology by tracing 

 the various stages in the development of the germ in the hen's egg. \Mule his 

 work along zoological lines has placed him in the-front rank of the scientists of his 

 own era, that on the botanical side has marked him out as one of the leading 

 naturalists of all times. When a biologist of such ability penetrates into a practi- 

 cally unexplored region as that presented by the subject of galls, it is to be ex- 

 pected that the progress made will be quite phenomenal, and this has proven to 

 be the case. The science of cecidology, Avith the founding of w^hich Malpighi must 

 be credited, was based l)y him upon taxonomic knowledge. His catalogue, " De 

 Gallis," published in 1686, contains descriptions of a large number of Italian and 

 Sicilian galls, and shows the intimate familiarity of the author with the included 

 types. Prior to this work, the galls that appeared in the literature were, with few 

 exceptions, confined to the rose, beech, and oak. But, in addition to such well- 

 known forms as Ehodiicf< rosa\, Andricus fecundatn.r, Cijnips KoUari, etc., he has 

 described others that are. less common and more restricted in their distribution. 

 For example, he collected Aijla.r glechoiufc I^inn. parasitic on Xc/ieta hederacca. a 

 gall that has been wddely introduced into America, and is almost certain to be 

 found wherever the Ground Ivy is established. He was also the first to observe 

 the beneficial gall nodules on the roots of Leguminous plants, and had noticed, as 

 well, Erineum galls without being familiar with their production by mites. The 

 deformities of this nature he has mentioned are those produced on Yitis and 

 Populus. Malpighi did not concern himself only \\\i\\ the characteristics of the 

 external form of galls, but applied his knowledge of plant anatomy to the investi- 

 gation of their internal structure. By this means he became familiar with tlie 

 course of development of several galls, and the typical stages of individual species. 



Valuable as was the contribution thus made by Malpighi to our botanical 

 knowledge of galls, it -was overshadowed by the importance of his work along 

 entomological lines. Indeed, the complexity and importance of the problem 

 presented by the production of galls was never fully appreciated until he dis- 

 covered their insect origin. Only then was the question seen clearly in its dual 

 character, involving a stimulation by the producer, and a reaction l)y the host. 



