546 MEROBLASTIC—MESOMYODI 



in 1771, and ornithologists generally,^ but the F. lithofalco'^ of 

 some — one of the most beautiful of the Falconidx (Falcon) and 

 perhaps the boldest of the Accipitres, not hesitating to attack 

 birds of twice its own size, and even on occasion threatening 

 human beings. Yet it readily becomes tame, if not affectionate, 

 when reclaimed, as it often is for Falconry, and its ordinary prey 

 consists of the smaller Passeres. Its " pinion of glossy blue " has 

 become almost proverbial, and a deep I'uddy blush suffuses its 

 lower parts ; but these are characteristic only of the male — the 

 female maintaining very nearly the sober brown plumage she wore 

 when as a nestling she left her lowly cradle in the heather. It 

 breeds or used to breed commonly on the moors of the northern 

 parts of England and on those of Scotland, as well as on the moun- 

 tainous districts of Ireland ; but of late years has been much reduced 

 in numbers. In winter the young frequent the lower levels in all 

 three kingdoms, and strike terror into the small birds that congre- 

 gate at that season. Very close to this bird comes the Pigeon- 

 Hawk, F. colwnbarkts, of North America — so close, indeed, that 

 none but an expert ornithologist can detect the difference. The 

 Turumti of Anglo-Indians, F. cJdcquera, and its representative from 

 Southern Africa, F. ruficoUis, also belong to this group, but they are 

 considerably larger than either of the former. 



MEROBLASTIC, the term applied to the ova of certain Verte- 

 brates, including Birds, in which the process of segmentation is 

 confined to the germinal disk (see Embryology, p. 196). 



MERRY-WING, a North-American fowler's name for the 

 Golden-eye. 



MERTYN, an old Scottish spelling of Martin. 



MESENTEPiY, the thin transparent membrane composed of 

 layers of connective tissue that holds together the various loops of 

 the intestine and other viscera, attaching them to the vertebral 

 column where it is continuous with the peritoneal lining of the 

 body cavity. 



MESOBLAST, the middle layer of the three into Avhich the 

 blastoderm subdivides (see Embryology, p. 200). 



MESOMYODI, Garrod's name {Froc. Zool. Soc. 1876, p. 507), 

 for a division of Passerine birds the peculiai'ities of which were 

 first to some extent though not fully appreciated by Johannes 

 Miiller (see Introduction) — "a mesomyodian bird being one in 

 which the muscles of the Syrfnx join the semi-rings in their 



^ Modern American authors call it Falco (or ^Esalon) regidun, a name given 

 in 1773 by Pallas {Ilcise, u.s.io. ii. p. 707). 



- This from the common German name Steinfalk. 



