TRANSACTIONS OF THE SECTIONS. 107 



forms after the manner of vertebral centra ; and there are indications of three of 

 these all becoming either fused into the basioccipital bone or absorbed. The basilar 

 or postpituitary region of the skull corresponds to not fewer than four body-seg- 

 ments, and possibly represents a considerably larger number. The osseous skull 

 supplies no data for fixing the total number of body-segments that have gone to 

 make up the skull. The segments discernible in the skulls of Mammalia do not 

 enable us to lay out the composition of lower skulls on that plan. The mammalian 

 skull is the culmination of an evolution, not the simple type to which all skulls are 

 to be referred. Many bones of the mammalian skull are modifications of bones 

 which primarily are scales and dermal bones in lower vertebrates, and have no 

 original relation to deep parts, and cannot receive names expressing vertebral 

 relations. 



On the use of the terms Assimilation and Metastasis. 

 ByG. T. Bettany, M.A., B.Sc. 



This paper urged the bringing about of a close unity between animal and vege- 

 table physiology by the use of terms in the same sense, and the expression of 

 processes in the same manner and wherever possible. The term assimilation is 

 now used in a total different manner in the two, and physiology is retarded thereby. 

 The manufacture of protoplasm out of food by pre-existing protoplasm is the 

 legitimate use of the term assimilation. It is much better to use other words for 

 other processes. " Chlorophyll-function " is an expression deserving of introduc- 

 tion. " Metastasis," or Stofiswechsel, as used by Sachs, covers much too wide an 

 area ; it should be restricted to changes occurring in order to the transport of 

 materials, and distinguished from assimilation. 



On the Mammillary and Accessory Processes as Persistent Epiphyses in tJie 

 Human Spine. By ~D. J. Cunningham, M.D., Senior Demonstrator of 

 Anatomy, University of Edinburgh. 



The author showed a vertebral column which he had obtained in the dissecting- 

 rooms of the Edinburgh University, and called the attention of the Department to 

 the following peculiarities which it exhibited. (1) Twelfth dorsal vertebra : the 

 mammillary processes were present as separate nodules of bone quite distinct from 

 the vertebra. (2) First Lumbar Vertebra: the mammillary and accessory pro- 

 cesses were fused and constituted on each side of the neural arch a V-shaped ossicle 

 in opposition with but not attached by osseous union to the vertebra. (3) The 

 tip of the spinous process of the first dorsal vertebra and the tip of the transverse 

 process of the seventh dorsal vertebra were also present in the form of ossicles, 

 unconnected by osseous union with the basal portion of the process. 



In the recent state all these ossicles were jointed to their respective vertebrae by 

 true diarthrodial joints. 



On the Myology of the Shoulder and Upper Arm of the Thylacme, Cuscus, 

 and Phascogalo. By D. J. Cunningham, M.D., Senior Demonstrator of 

 Anatomy, University of Edinburgh. 



Towards the close of last Winter Session I was so fortunate as to obtain, for the 

 purpose of anatomical research, all the marsupial animals brought home by the 

 * Challenger Expedition.' In the present instance I purpose confining my remarks 

 entirely to the anatomy of the shoulder and upper arm of three of the least-knc 

 of these specimens, viz. the Thylacinus c/noccphalus, the Phalanyista maculuta or 

 Cuscus, and the Pkascoyale calura. 



Myology. 



Trapezius. — This muscle, which springs from the occipital crest, the spines of all 



