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F. E. BEDDARD ON THE ANATOMY OF [May 26, 



with the usual rotation of Stage II., and there is also invariably 

 a connection of the omentum wdth the colon, and furthermore, 

 always a secondary connection of the duodenum with the colon at 

 its commencement. This stage is represented by Lemurs (the 

 majority), all of the Hyracoidea, Perissodactyla * and Artio- 

 dactyla f, and, finally, Rodents. 



Text-fig. 123. 



Diagram of Mammalian intestine, Stage III. 



a.c.d. Ansa eoli dextva. a.c.s. Ansa coli sinistra, a.p. Ansa paracEecalis. 

 c.d. Colico-duodenal ligament. Other letters as in text-fig. 120. 



This Stage is hardly divisible into difi'erent grades. There are, 

 it is true, simpler forms and more complexly convoluted colons. 

 It might perhaps be permissible to place at the base of the series 

 the Perissodactyla and Hyracoidea where thei'e is but one ansa 

 coli, and that apparently the ansa pai-actecalis of other types. If 

 Klaatsch be right in regarding the coil of Ruminants and Swine 

 as an ansa paractecalis, this group would be added. In this case 

 we arrive at the interesting conclusion that the colic spiral is not 

 strictly homologous through those groups which show it. For in 

 the Lemurs it cannot be doubted that the spiral is the ansa coli 

 dextra. It is only the Rodentia which show the maximum of 

 coiling of the colon, and in the more diflferentiated genera of that 

 order (e. g. Castor) there are three ansae coli, though not more, 



* I liave not dealt above in detail with the single simple ansa coli of Horses, Tapir, 

 and Rhinoceroses, since it has been so often described. 



t See especially Lonnberg, Acta Ac. Upsala, 1903, K. Vet.-Ak. Handl. 1901, and 

 some other memoirs. 



