No. 500] NOTES AND LITERATURE 



551 



published in February, 1907, under the title "A Study of Fun- 

 damental Bars in Feathers" (Biol. Bull, XII, 1907, pp. 165- 

 174) the author gave a resume of the results of studies here 

 extended and for the first time fully set forth. The existence 

 of "fundamental bars" in feathers was discovered by Whitman 

 in the summer of 1902 (not published till 1907), who found 

 them "to be common to all species of pigeons and birds in gen- 

 eral," and that they "appear to mark all feathers of all species 

 of birds." 2 The present research was undertaken at Professor 

 Whitman's suggestion, whose observations furnished the start- 

 ing point for these studies. These are: "First, there is in all 

 feathers a 'fundamental barrinu' of the whole length of the 

 feather; second, certain defects (fault-bars) occasionally appear 

 in the plumages of birds reared under adverse conditions.'' 

 The fault-bars are considered as regards (1) their morphology, 

 (2) their extent and distribution, (3) their cause. Whitman's 

 suggestion that fault-bars are due to malnutrition has been 

 abundantly proved by experimental research. While normally 

 due to lack of nutrition, they may be produced by feeding birds 

 on Sudan III, by mechanical injury of the feather germs, by 



interrelated facts bearing upon this assumption are thus stated: 

 "(1) Diminished feeding of birds produces emphasized fault- 

 bars. (2) Artificially reduced (amyl nitrite) blood-pressures 

 produce equivalent defects. (3) The fault-bars are produced 

 at night. (5) The lowest daily temperature in birds occurs 

 from 1:00 a.m. to 5:00 a.m. (6) Other physiological con- 

 ditions of the bird seem to be favorable at night for the produc- 



