ME. E. DEGEN ON ECDTSI8. 373 



has only reached the stage of development of a pin-feather, whose extreme barbs have 

 just pierced the tip of its accompanying capsule. In text-fig. 3 these feathers are 

 marked respectively, remiges IV., III., II., and I., in the order described above. 



Another specimen received on the same date (January 16th) as the previous one, to 

 which I have given the serial number 20, also shows the whole of this set in full 

 process of moult on both sides of the wing, but is in a rather more advanced stage 

 throughout. 



Two specimens, Nos. 21 and 22, dating from January 29th, out of the total comple- 

 ment for that week, which also includes No. 23, also partake in this phase of the moult. 

 No. 22 is slightly belated if compared with No. 20, whose early-accomplished -pennoe 

 pollices correspond with the moult of metacarpo-digital remiges V., VI., VII., and 

 VIII. respectively ; whilst in the case for the left side of No. 21, they correspond 

 with primaries VI., VII., VIII., and IX. The right side is later still, where the 4th 

 feather is the only one as yet replaced ; this corresponds with metacarpo-digital 

 remex VII. 



Specimen 22, for an old female, presents a case of later appearance still, and, 

 moreover, shows the additional anomaly of simultaneously producing (but symmetrically 

 for both sides) the fourth and the second quills, whereby it has missed the renewal of 

 the intervening third quill. The impending moult of this latter is indicated by its 

 point just showing above the epidermis on the right side only, thus, as it were, rapidly 

 remedying the deficiency. Seeing that this is the only specimen out of four quite 

 normally moulting individuals, this case can be little else than the result of a faulty 

 individual constitution. 



In the remainder of the specimens received after this period, the moult of this series 

 of feathers was invariably accomplished. It, moreover, shows that their moult is 

 identical in period with that of certain primary remiges, and corresponds almost 

 exactly with the extreme digital ones by slightly fluctuating between metacarpo- 

 digitals VI. and X. 



The relative position for the growth of these pennte pollices to those primaries with 

 which they moult in synchronism, based upon the highest aggregates received for each 

 feather separately, will be found entered on Table VI., which is at the end of the 

 technical description dealing with the feather-tracts in general. 



The moult of these jpennce is of ever so much greater importance than their purely 

 ordmal replacement when considered from the point of digital feathering as a whole. 

 Whether the origin be a doubtfully remigial ^ or an admittedly tectrical one only is of 

 no consequence in this place. At the most their metacarpo-digital value must remain 

 undisputed, since the principal satellites, as will be seen, also reflect the ordinal 



^ The similar absence of sedentary neossoptiles on the tips of the first set of these feathers, the same as in 

 the other remiges, ought, in my opinion, to be decisive on this point. 



8 g2 



