46 IOWA ACADEMY OF SCIENCES. 



portant step in the argument is taken when we discover that the true concealed crests 

 are always found among inseclirorous birds, and nowhere else, so far as I can dis- 

 cover, among American birds, at least. ^ They occur among the Ti/rannidce Oxy- 

 rhamphidw, Pipridw, Tanagridce and the ReguUnce. 



Mow, all of these birds are essentially insectivorous and I have been unable to find 



Now, when we add to these considerations and facts the observations of Mr. 

 Beckham on the Kingbird, and myself on Mitscivora mexicana, in which cases 

 the crests were seen to be of direct service in alluring insects; the theory may be 

 regarded as practically demonstrated, although a larger number of observations 

 is greatly to be desired. 



Another interesting fact is that all of these crests are erectile, and are conspic- 

 uous when erected, and partially or completely concealed when not erected. In- 

 sectivorous birds which are without these crests often erect the feathers of the 

 crown when excited by anger or the proximity of food. I noticed last summer, 

 while visiting Mr. Ridgway, that his pet song-thrush always erected its crown 

 feathers when about to peck a fly from anyone's fingers, which was its habitual 

 way of feeding. 



Many Tyrannidce have yellow or red as part of their general coloration. Some 

 of these colors at the bases of the crown feathers would be exposed when the 

 feathers are erected in the excitement incident on the approach of insect prey. 

 If this tended to benefit the bird by attracting the insects, natural selection would 

 preserve and intensify it, and we may thus see the means or method by which 

 concealed crests may have originated. 



It may be suggested in conclusion that these concealed crests are probably among 

 Nature's latest devices wherewith she has equipped her feathered favorites. 

 The fact that they appear among the most highly specialized genera of the Tyran- 

 nidce, and are often specific and not generic characters, shows them to be lately ac- 

 quired. Another indication of the same truth lies in the fact that, in many spe- 

 cies, at least, the crests are acquired rather late in life, young birds having little 

 or no trace of it. 



PHONOLOGICAL NOTES FOR 1892. 



BY L. H. PAMMEL. 



It has always seemed to me that there is abundant room for such botanists 

 as have little time to do original work to devote a few moments in 

 taking notes on the leafing, flowering and ripening of seeds of our native 

 and cultivated plants, in short everything that may be considered under the 

 head of pha?nological observations. These observations, like those on the 

 pollination of flowers may be made at odd moments and would be of great 

 service to working botanists. If a few scattering botanists would only col- 

 lect insects on various flowers and make field observations, then turn them 

 over to a botanist like Mr. Roberts, it would be of incalculable benefit. So, 

 too, in this pha?nological work botanists all over the country should make a 

 few observations, bring them together so that some general conclusions 



iThere may be other cases amons Central and South American birds, as lack of time 

 prevented my going through the whole series as carefully as I could have desired. 

 a single well-defined concealed crest which is possessed by anon-insectivorous bird. 



