The Structure and Functions of the haemolymph Glands and Spleen. 23 



vogue for studying the framework of glandular organs. In some cases 

 the fresh tissues have been cut with the freezing microtome, and sub- 

 sequently treated with a 5^/q solution of caustic potash; in other 

 cases they have been submitted to tryptic digestion, or the blood has 

 been removed from the sinuses by washing with distilled water. Yet 

 again, the entire gland was first hardened in alcohol, treated with a 

 I^Iq solution of caustic potash, and afterwards transferred once more 

 to alcohol. The further treatment was as follows: — the gland was 

 either stained in bulk, or mounted unstained in paraffin, and sections 

 were then cut and mounted. 



In the study of a number of preparations by these different 

 methods, I have observed little or no difference between the structure 

 of reticulum in these and related glands. My observations on the 

 general arrangement of the tissue agrees with the description given 

 by Professor Schäfer^) in ordinary lymphatic glands. Fibrous con- 

 nective tissue forms the foundation of the whole organ, and it is most 

 compact in the capsule and trabeculae, consisting essentially of bundles 

 of white fibres; fine strands pass from these in every direction, forming 

 a dense meshwork which supports the other tissue elements of the 

 gland. The reticulum is very dense in the adenoid tissue, but more 

 sparse in the sinuses: between sinus and lymphoid tissue, or, more 

 correctly, in the outermost part of the lymphoid tissue, the reticulum 

 becomes denser (c. f. spleen, pi. II. fig. 16). A question of considerable 

 difficulty arises with regard to that portion of the reticulum which 

 bridges across the sinuses. It has been regarded by Schumacher and 

 others as consisting of numerous branched cells, the processes of which 

 interlace, giving rise to the characteristic appearance of a network: 

 and it is noticeable that many of our standard text books illustrate 

 it as having this structure, in the case of lymphatic glands. Recent 

 observers, in particular Höhl [6], consider that the reticulum consists 

 of a fibrous network with flattened cells, which he calls '''reticulum 

 cells'^, attached to it. In the case of the haemal glands this is certainly 

 the arrangement, although the nature of the reticulum cells themselves 

 appears at present not to be clearly understood. 



^) Quains Anatomy. Vol. III. Part IV. p. 296. 



