■106 I^lH. K BKGEN ON ECrA'SlS. 



coming on next above tlu; greater coverts, indicated by the letter C {intercalary row) 

 in the following diagram, is seen to consist of a series numbering generally five or six, 

 Mhich are confined to the distal areas of the cubital region, and form a distinct and 

 separate series from the feathers that extend across the median area. They corresjjond 

 ■ill relative position to the upper wing-coverts (t.m.) in the manual region of the wing'' ', 

 Sec. And further on : — " The feathers referred to often form a conspicuous feature on 

 the wing of the living bird, as they are frequently arranged in such a manner tliat the 

 shafts of three or more of the feathers are in a line. The j^'i'oximal edges of thp 

 feathers are generally as fnn as those on the opposite side ^ and, as a consequence, 

 tiie whole series slides between the feathers next them on the proximal side in much 

 the same way as the blade of a lancet closes in its sheath," &c. 



Wray (46) also drew attention to this set of feathers, and after rectifying in his 

 paper a few incongruities which arose out of Goodchild's nomenclature for the 

 grouping of portions of the series on the wrist, dismisses the subject (p. 350, I. c.) with 

 the following remark : — 



" Grouping the feathers according to their insertion, and remembering the conditions 

 of folding which must occur on the wrist, the observations of Goodchild give the most 

 complete view of this subject we have." 



It is in Pycraft's excellent thesis (39) that the greatest amount of significance 

 as yet attached to the presence — better expressed appearance — of this set of flight- 

 feathers called the "intercalary row" has been most signally pointed out. But how 

 much the introduction of this element became responsible in the " shifting process " 

 (chiefly transverse) of all the rows of the distal portion on the forearm, with its 

 consequent '• faulting," a glance at the drawing of his own preparation, of the nestling 

 Jjomvia troile {cf fig. 2, p. 243, I. c), suffices to show. He thus lucidly describes it : — 



" The disturbance is much more obvious in the row of papillae immediately above 

 the remiges — the rudimentary major coverts 1-5. These have become distinctly 

 separated from the rest of the row proximad of this point. The disturbance of the 

 rows preaxial to this of the major coverts is barely perceptible. There is yet no 

 intercalary row " ^ 



Why, in spite of the impendingly disturbing influence they exert at this critical 

 stage, he never so much as attributed to them the real cause of the general disturbance 

 w'hich his later stage (of the above figure mentioned) so clearly demonstrates, seems 

 incomprehensible now, although clearly capable of explanation. The reason is that 

 he connected them — upon their sudden appearance — embryo-genetically with the 

 members of the rows of either the Medians, or those above the latter, e. g. the Minors, 

 entertaining even some slight doubts about their serial value as regards the latter's 

 first or second row ; instead of treating them as the real cause which separates the 



' These italics are miue. 



