2 SOME ASPECTS OF MORPHOLOGY 



the taxonomist. The difficult subject of the genitaUa, especially 

 when taken in conjunction with the facts of development, is 

 becoming more clarified and we are beginning to see an underlying 

 fundamental similarity in these parts. It is to be deplored 

 that morphology, as a whole, is becoming involved in a con- 

 fusing terminology and a consistent nomenclature will sooner 

 or later have to be adopted if a complex synonomy is to be 

 avoided. 



The most significant change of attitude to-day is seen in the 

 increasing appreciation of the importance of insect physiology. A 

 vast literature on this subject already exists ; most of the older 

 work is now of little value in view of the great progress made in 

 experimental technique. Some idea of the recent growth of this 

 subject may be gathered from a valuable article by Hoskins and 

 Craig (1935). These authors mention having considered some 

 1,200 papers published during the five years 1931-35, and they 

 cite 444 of these in the useful bibliography which is appended. 

 We may pause for a moment and consider the causes contributing 

 to the rapid growth of this type of investigation. For one thing, 

 the applied entomologist, in his efforts to find a surer foundation 

 than purely empirical methods for the control of noxious insects, 

 is devoting attention to the possibilities of insect physiology. 

 He is realising that the most promising line of approach lies in a 

 better knowledge of the inner working of insects themselves. The 

 growing importance of insects as carriers of disease organisms of 

 man and domestic animals is likewise creating a demand for similar 

 knowledge. Applied entomology, therefore, as a whole, in its 

 need for information of this kind, is focussing the attention of 

 many workers on physiological problems. It needs also to be 

 remembered that the rapid growth of the experimental viewpoint 

 among general zoologists is another contributing influence, since 

 an increasing number of zoologists is being attracted to the study 

 of problems of a physiological nature afforded by the insect 

 world. Already more than one academic body has been led to 

 provide for some measure of teaching and research in insect 

 physiology. A very large literature on the subject in question is 

 appearing in an extraordinary diversity of periodicals, many pf 



