312 



SCIENCE. 



[N. S. Vol. XXIV. No. 610. 



that there is something to keep the grasshoppers 

 and other insects in check (pp. 101-2). 



The statements in this paragraph seem elo- 

 quent of the spirit of the man. He found 

 out many things that others did not know 

 and strove after a genuine appreciation of 

 the relations of things ahout him. He was 

 one of the earliest to take the direct method 

 of doing this in the field of American eco- 

 nomic ornithology. That his work has re- 

 mained unnoticed because of a name is a pity. 

 His observations are not trite to-day, but, on 

 the contrary, they possess freshness, almost 

 novelty. That such is the case after a lapse 

 of more than forty years is a significant trib- 

 ute to an able and original man. 



W. L. MoAtee. 

 Biological Suea^et, 

 Washington, D. C. 



GALL-INSECTS AND INSECT-GALLS. 



In no phase of biological work are the re- 

 sults of the neglect of cooperation more ap- 

 parent than in the study of ' insect-galls ' and 

 ' gall-insects.' In fact many of our best sci- 

 entists fail to recognize the two closely re- 

 lated subjects as distinct and continue to use 

 the terms synonymously, although the one is 

 botanical while the other is entomological. 

 The entomologists have given considerable at- 

 tention to the study of gall-insects, but the 

 study of insect-galls has been woefully 

 neglected, while lack of cooperation has made 

 much of our entomological knowledge of ques- 

 tionable value. 



For some time the writer has been bring- 

 ing together the literature upon these two 

 subjects, and it may be of interest to the read- 

 ers of Science to see a summarization of the 

 work in hand at this time. The six orders of 

 insects containing gall-makers,, include 16 

 families, 77 genera and 583 species (not count- 

 ing leaf curlers and those for which galls 

 have not been described, but which we have 

 every reason to suppose are true gall-makers). 

 These galls arranged with reference to the 

 host plants show the following: 26 orders, 51 

 families, 90 genera and 18,8 species affected. 

 Of the 26 orders 12 show only one family in 

 each to be affected; of 51 families 26 have 



only one genus affected; of the 90 genera 63 

 have only one species in each affected. The 

 genus Quercus leads with 45 affected species 

 aiid Salix is second with ten affected species. 



These figures are absurd and every student 

 of either entomology or botany believes that 

 the list of host plants should be much longer. 



Let us look for an explanation: (1) The 

 botanist has given practically no attention to 

 the subject, although every herbarium of im- 

 portance contains more or less galls that have 

 been incidentally collected. (2) The ento- 

 mologists have studied the insects rather than 

 the galls and too often their descriptions of 

 the galls have been indefinite. Furthermore, 

 the determinations of the host plants in many 

 cases have been uncertain or entirely omitted. 

 Papers have been published without giving 

 the common names of the hosts, others with 

 only the common names, others with only the 

 generic names and others in which it is evi- 

 dent that the determinations are incorrect. A 

 well-known botanist in examining my list 

 recently remarked : ' Here you have a number 

 of galls attributed to a single host plant, while 

 I have seen galls on four different species of 

 that genus.' Yet, I have reason to believe 

 that I have examined practically all the North 

 American literature on the group of gall- 

 formers to which he referred. I have also 

 received from well-known entomologists, galls 

 of the same species bearing different names. 



The study of the insect-galls and their 

 makers, parasites and inquilines presents a 

 very large number of interesting problems of 

 which the following may be mentioned: (1) 

 We know very little concerning the dimor- 

 phism of the American species. (2) We know 

 nothing of the relation of the distribution of 

 the insect, to the distribution of the host plant. 

 (3) We have very little reliable data concern- 

 ing the ability of any one species of insect to 

 produce galls upon more than one species of 

 host plants. (4) Very little has been done 

 on the anatomy of the American galls. (5) 

 Very little has been done on the physiology of 

 the galls. 



Mel. T. Cook. 



EsTAciON Central Agkonomica, 

 Santiago de las Vegas, Cuba. 



