No. 027] GERM PLAS^f OF THE OSTBICJI 



325 



tion from the maximuin 42 to the present nnnimniu of 33. 

 As experiments have pi'oved that the liigli num])er l)reeds 

 true, and as the other rows of commercial plumes vary in 

 correlation with the remiges, the discovery has a great 

 industrial bearing; for it now becomes possible to pro- 

 vide the farmer with a pure line of 42-plumed ostriches 

 in place of the degenerate 3()-phimed birds with which he 

 farms to-day, and the entire feather crop will sufi)ass the 

 present one by about 25 ])er cent. 



The first row of upper-coverts varies in correlation 

 with tlie remiges (Fig. 2) but never shows any indepen- 

 dent reduction, W'liile the second row has often a number 

 missing from its distal end, and is clearly undergoing 

 reduction here in contrast with the elbow end for the 

 under-coverts. Again, it is usually stated by writers that 

 the ostrich is destitute of an under-covering of down 

 feathers and filoplumos. yei in every northern and 

 southern bird exaitiiiUMl. ddwii in all -tages of degenera- 

 tion occurs arou7id tlu- Isi-r of the larger plumes of the 

 wing and tail, and in v;\rr ci-cs >iir( ;i(ls over a wider area, 

 leading to the conclusion tli;it ;it niic time tlu^ osti-ich had 

 an under-covering of -iiinll rcnllicr- like flyinii' hirds 

 generally. 



The tiiird digit di^plax^ rcrlwiii nio^i unrxprrird .-vo- 

 lutionarv >tngcs. AVliilc in ni.>^l m^.- it nllnuvthcr em- 

 beddod in tli(^ tlc^h of the winu-. nno mn on!\ I,.- M>en and 

 felt llirougli the lliin >kin. yet orrn-ionn II \ il> li]) ])ro.iects 

 quite freely, suggc-tinu- it- t*..r:iifi' M-|iai-nt ion. like the 

 first digit which fornix the nla ^i-uria. :\loivov(.r, in some 

 birds odd feathei's arc to he found .-d alojtu- the finger, 

 altogether detached from an\ (»tlici' -eric-. Tliese are 

 surclv to he un<h"i-to.Ml a^ -arxivaU nf a time when the 

 thir.l fimi.T wa^ riawed. fivr an.l iu'ovide<l with it> own 

 feathoi-. a prinnlive condition wliieli UHiaily hvU\ to 

 be represented (Uily in the oldest known fo»il bird, 

 Archccoptcryx. 



The legs and toes likewise exhibit degenerative phases. 

 The African ostrich is unique among living birds in hav- 



