368 NATURAL HISTORY OF BIRDS. 



Order XVII. — PICARI^. 



Coinciding with Professor Newton's words, th:it the Picarite "are already a sufli- 

 cieiitly hc'tiTogfiieoiis asseiiiMiigc " to also iiicluclo the owls, we retained the latter 

 at the end of the lla])tores, though ailiiulliiig that this group, thereby, beeomes 

 even more heterogeneous than the Piearians. But, true to our jirineiple of not 

 exeliaiiLriiig <>iie doubtful eoiirse for another e(jually doubtful, we think it safer to 

 adhcrt- to the arrangunu'nt adopted. That we havu here indieated the true course of 

 development of .some of tlie Picariie at least, — the goatsuckers and their allies, — 

 seems, howi-ver, less doubtful. Another line of descent seems to connect certain 

 forms included in the ju'csent order with the (iallinaeeous birds, througli the Muso- 

 phagidoB. If this view be correct, then the 'onler' Picaria- will have to be 8]>lit u|i 

 according to its double descent. 



To the scientilic ornithologist, the Picaria? form an assemblage of the greatest 

 interest. Their anatomy has in many instances l)een worked up pretty well, and has 

 disclosed a multitude of characters, generalized as well as specialized, extremely 

 marked, but pointing in all directions. Numerous classificatory attempts have been 

 ma<le, based ui)on the most different ])riTiciples, ;iMd the most varied sets of characters; 

 still, whether based upon external or internal structure, the general a8i>ects of these 

 different systems show greater similarity than might be expected. Messrs. Garrod 

 and Forbes liave es])ecially elucidated the anatomy of tlie Piearians, and their oj)in- 

 ions .are, therefore, entitled to sjieeial consideration. A brief summary of the more 

 imi)ortant structural features of the different groups is therefore necessary, the more 

 so since we are obliged to dissent from some of the conclusions of these gentlemen. 



Mr. Garroil divided the forms here included into two main divisions, — the llomal- 

 ogonata", which possess the ambiens muscle, and the Anomalogonata;, wliich do not 

 have it. The former, viz. the Cuculida> and 3Iusophagi<he, he referred sim|)ly .as 

 families to the 'order' Gallifonnes, while of the latter, plus the Passere.s, he made an 

 'order' under the above name. This order he again subdivided in Picifoimes, Passer- 

 iformes, and Cy|)seliformc8. The last mentioned group is generally admitted to be 

 natural and distinct ; the other two, and the removal of the Coccygiformes, are rather 

 novel features, and need explanation. 



The Cuculidai and Muso])hagiil;e are zygodactylous, i.e., they have two toes in 

 front aiul two behind, like the woodpeckers and allied forms, with which they have 

 usually been jilaced. The structure of the foot is so characteristic that more than the 

 presence of the and)iens muscle would be re(juiretl to remove them from that neigh- 

 borhood. Sucli additional features are also found in the skeleton, as well as in the 

 myology and plcrylography. Not to go too deep into details, we shall oidy refer to 

 the arrangement of the muscles that bcn<l the toes, viz. the deep plantar tendons. In 

 the introduction (page 14), mention is made of the fact that in the Cuculidae and 

 Musophagida? X]\q flej-or perforann splits up to supply second, third, and fourth digits 

 or toes, i.e. to the three toes which in most other l)irds are directed forwards, while 

 Xhc flexor hallucis is single, and only goes to the hallux ; this arrangement is the origi- 

 nal one, as it seems, and the commonest amongst the birds, hence we call it iiomojyel- 

 moiis; in the cuckoos, j)arrots, gallinaceous birds, the two tendons are united at their 

 crossing ])oint by a vinculum; these are therefore called desniopelmous, while the 



