Igr1] COOK—PROBLEMS IN CECIDOLOGY 387 
of both the egg (i.e., the gall) and the insect which emerged from it, 
and determined their specific characters. As in all other biological 
subjects, the first real scientific work was taxonomic in character, 
and in 1686 Ma.picut, who was a physician to Innocent XII and 
professor of medicine in Bologna and later in Messina, published 
his De Gallis, in which he gave quite accurate descriptions of the 
known galls of Italy and Sicily. Following this work, which may 
be looked upon as the starting point for cecidology, LINNAEUS and 
many other later writers gave more or less attention to this subject, 
which has attracted so much attention in Europe during recent 
years. _ In America, the pioneers in this subject were Baron C. R. 
OsTEN-SACKEN, BaAssETT, WALSH, Ritey, Fitcu, SHIMER, and 
Harris, all of whom were entomologists. 
Although the entomologists have done more work in cecidology 
in both Europe and America than the botanists, their work has 
been no broader. The entomologists have studied the insects 
and described the cecidia which were attributed to them, and in 
the case of the injurious species have devised means for their con- 
trol. The botanists have done the same work for fungi which cause 
cecidia, and have also invaded the fields of the bacteriologist and 
zoologist and studied not only the cecidia produced by bacteria 
and nematodes, but have even studied the organisms. 
Taxonomy seems to be the forerunner of all lines of biological 
work, and this has been true of cecidology, but we have now reached 
@ point from which we can extend our studies into other phases of 
the subject. We can now study the subject with reference to 
other phases of biology, in fact other phases of biology are encroach- 
ing upon the subject of cecidology. With this new development, 
the entomologist, the mycologist, and others will continue to find 
ample fields for the study of taxonomy. The entomologist will 
also have those almost untouched fields of life history and of alter- 
hation of generations which came so near to demonstration by our 
fellow-countrymen, H. F. Bassett, and which was afterward demon- 
Strated by HERMAN ADLER. 
The various groups of botanists will find especially. rich and 
almost untouched fields in many directions. The anatomical 
and histological characters and the development of cecidia have 
