654 



DR. P. CHALMERS MITCHELL ON THE 



Dec. 17 



modification in one direction of the Eurypyga type. Its peculiarity 

 is that the divisions of the haUucis tendon for the digits unite with 

 the similar divisions of the profundus tendon only very close to 

 the insei'tions. The conditions in the other members of the 

 Giaiiformes, as will be apparent without description from the 

 drawings in text-fig. 85, can easily be explained as apocentric modi- 

 fications in a different dii'ection, consisting in further specialization 



Text-fijT. 85. 



Deep plantar tendons of Gruiformes. 



I. EaUus and Tsofhia. 

 V. Otis. VI. Shinochehcs. 



II. Balearica. III. Aramus. IV. Cariama. 

 VII. Eiirypyga. VIII. HeUornis. 



The hallux in all is to the left ; the arabic numerals represent the digits ; 

 the flexor lougus hallucis is in while ; the flexor perforans sen profundus 

 is deeply sliaded. 



of tlie hallucis tendon and withdrawal from supply to the digits 

 other than the hallux. The vinculum seen in the case of Rattvs 

 and PsopJiia (text-fig. 85, I), and which is found in a large number 

 of birds, appears to be a Jate stage in the withdrawal of the hallucis 

 tendon from the other digits, and not, as it often has been regarded, 

 as a simple condition. It is plain, however, that these junctions 

 show in the same fashion as many of the other structures I have 

 passed in review, that while there is a general similarity among 

 the members of the G-ruiform assemblage, there is little close 

 coherence in the group. 



