8 DEVELOPMENT OF LYMPHATIC SYSTEM, FISHES 



Cuvierian junction, may be either single or multiple in charac- 

 ter. In addition to these more typical points of communication, 

 the lateral pharyngeal lymphatic may also coimnunicate with the 

 precardinal at almost any point between the two; so that the 

 region of the precardinal vein which hes between the otic (13) 

 and cardino-Cuvierian communications (9) may be regarded, 

 in general, as constituting a district of lymphatico-venous 

 communication. 



2. The subocular lymph sacs (1 in figure 10, saccus lyinphaticus 



subocularis) 



The subocular lymph sacs consist of two relatively huge sacs, 

 each of which is situated ventro-medially to the eye. They are 

 more or less triangular in form, with their apices directed ante- 

 riorly. In the twenty-two-day trout under consideration, they 

 extend between the hyoidean artery (15) and the olfactory pit 

 (33 in fig. 14). They do not communicate with each other nor 

 with the veins in the immediate neighborhood of the sacs. At its 

 posterior lateral angle, each subocular lymph sac communicates 

 directly with the lateral pharyngeal lymphatic (3) of its respec- 

 tive side and drains through the latter into the veins at the 

 typical points of communication, mentioned above, which the 

 lateral pharyngeal lymphatic establishes with the veins (9 and 

 13 in fig. 10). 



3. The medial pharyngeal lymphatic (4 in figure 10, truncus 



lymphaticus pharyngeus medialis) 



This vessel occupies a more medial position and is more 

 deeply situated than the lateral pharyngeal lymphatic. It runs 

 an oblique course, in a postero-anterior direction, from about the 

 middle of the lateral pharyngeal lymphatic, with which it sub- 

 sequently establishes a communication, to open into the pre- 

 cardinal (jugular) vein just caudal to the point where the latter 

 emerges from the cranial cavity. This communication (medial 

 pharyngeal communication, 2 in fig. 10), together with those 



