BY W. J. McKAY. 925 



prsesacralen Wirbel in die postsacralen iibergehea, die Rippen und 

 die Processus costo-transversariieineGabelbildungzam Schutz der 

 Lymphherzen bilden. Salle, welcher sich rait ihrem Bau ausfiihr- 

 licher beschaftigt hat, nennt dieselben, " Lymphapophysen," und 

 je nachdem die Gabelbildung an den Rippen oder an den Pro- 

 cessus costo-transversarii (Querfortsatz, Salle) vorkommt "costale" 

 oder trans versale costo-transversale." And again, " Was die Ent- 

 wickelungsgeschichte der Lymphapophysen angeht, so theilt Salle 

 mit, dass beide Schenkel gleichzeitig von einergemeinsamen Basis 

 auswachsen, Knorpelig angelegt werden und spater ossificiren." 

 In endeavouring to account for the homology of the parts we are 

 met with this difficulty. If we take Salle's observation as 

 correct, both processes spring from the one point, then the 

 process that is in connection with ribs must either represent both 

 processes coalesced into one and differentiated off from the vertebrae, 

 or else it contains only the representative of one of the processes ; 

 or thirdly, that it has no connection with either of the posterior 

 elements. If we were to suppose that the rib was an outgrowth 

 from the side of the vertebra, our difficulty would thqji vanish, for 

 we would then have two processes springing from the vertebra in 

 each case, but being differentiated off in the one instance, and 

 remaining attached in the other. To this it must be said that all 

 late investigations tend to show that the ribs are not an outgrowth 

 from the vertebrae, but are formed quiteindependently. The question 

 arises, can even development prove the homology of the process 

 attached to the ribs 1 We doubt if it could ; for were it to be 

 shown that the process arose independently of the vertebra, then 

 the objection remains that the posterior ones are outgrowths from 

 the vertebrae. And if, on the other hand, the process arises as an 

 outgrowth like the posterior one, then which of the two does it 

 represent 1 



The fact seems to be clear, that, as regards the actual position 

 of the two processes, the superior corresponds to the detached 

 process connected with the rib, while the inferior corresponds to 

 the rib itself. If this be so then we think that the following 

 statement by Flower may throw some light on the subject : — 



