THE REGION OF THE SPINAL CORD 423 



existence in Pantopoda of a double set of glands of similar character, 

 one set in the basal segments of the appendage, and the other in 

 the adjacent part of the body. 



In scorpions also, Kowalewsky has shown that the remarkable 

 lymphatic organ situated along the whole length of the nerve-cord in 

 the abdominal region takes up carmine grains and bacilli ; an organ 

 which in Androctonus does not form one continuous gland, but a 

 number of separate, apparently irregularly grouped, glandular bodies. 



In addition to this median lymphatic gland, Kowalewsky has 

 discovered in the scorpion a pair of lateral glands, to which he gives 

 the name of lymphoid glands, which communicate with the thoracic 

 body-cavity {i.e. the pseudocode), are phagocytic, and, according to 

 him, give origin to leucocytes by the proliferation of their lining 

 cells, thus, as he remarks, reminding us of the nephridial capsules 

 of Clepsine. These glands are so closely related in position to the 

 coxal glands on each side that he has often thought that the lumen 

 of the gland communicated with that of the coxal gland ; he, how- 

 ever, has persuaded himself that there is no true communication 

 between the two glands. Neither of these organs appears to be 

 segmental, and until we know how they are developed it is not 

 possible to say whether they represent fused segmental organs or not. 



The evidence, then, is very strong that in the Crustacea and 

 Arachnida the original segmental excretory organs do not disappear, 

 but remain as ductless glands, of the nature of lymphatic glands, 

 which supply leucocytes to the system. 



Further, the evidence shows that the nephric organs, or parts of 

 the ccelom in close connection with these organs, maybe transformed 

 into ductless glands, which do not necessarily contain free leucocytes 

 as do lymph-glands, but yet are of such great importance as excretory 

 organs that their removal profoundly modifies the condition of the 

 animal. Such a gland is the so-called adrenal or suprarenal body, 

 disease of which is a feature of Addison's disease ; a gland which 

 forms and presumably passes into the blood a substance of remark- 

 able power in causing contraction of blood-vessels, a substance which 

 has lately been prepared in crystalline form by Jokichi Takamine, 

 and called by him " adrenalin " ; a gland, therefore, of very distinctly 

 peculiar properties, which cannot be regarded as rudimentary, but is 

 of vital importance for the due maintenance of the healthy state. 



In the Elasmobranchs two separate glandular organs have been 



