THE HISTOLOGY OF THE BLOOD OF LARVA OF LEPIDOSIREN PARADOXA. 447 
the Teleosteans (B1zzozERo, ZIEGLER, LAGUESSE, FELIX, and others). Inthe Lepidosiren 
larva the tissue is not true lymphoid tissue, as we understand the term in higher forms, 
and there are no glands. It consists simply of a tract of branched connective-tissue 
cells, with wide intervening spaces in which there are free lymph cells. Throughout 
the whole of larval life it has much the appearance of the mesenchyme at its first 
Fic, 2.—Section through larva, stage 32+, further back than figure 1, through liver ducts. x33 d. 
A, aorta; L, lung; Pr., pronephros; G, glomerulus; S, stomach; H.V., vena revehens of liver; Y, mass of 
undifferentiated yolk cells ; M, mesenchyme covering mass of yolk cells. 
appearance, and is, as it were, a tract of that tissue which has retained its undifferentiated 
characters. 
Feix * shows that in Salmonide it is not true lymphoid tissue, and he uses the term 
‘pseudo-lymphoid’ tissue. The tissue in the Teleosts, as described by him, differs both in 
appearance and development from the corresponding tract in Lepidosiren. To this I 
shall return later. 
At stage 32 the general disposition of parts is indicated in the diagrams in the 
text. In figs. 1 and 2 the still solid gut is seen lying dorsal to the liver; further back 
* Anatomische Hefte, Bd. 8. 
