353 



Presence of Haemoglobin in other regions of the 

 body, and of an orange-coloured pigment. 



The dark red perivisceral liquid may be completely washed away 

 from the Thalassema which has been opened in a dissecting trough so 

 as to permit of the examination of the natural colours of the chief or- 

 gans. It is then seen that certain parts are coloured with a bright 

 orange-red pigment which is similar to that described by Greeff in 

 Echiurus and has a similar disposition. This orange pigment occurs 

 on the surface of 1) the vascular trunks where it is most intense, 

 2) on the sheath of the nerve-cord, 3) on a median line extending 

 along the intestine from the termination of the chief vascular trunk, 

 4) on the surface of the four genital pouches (anterior nephridia) , 5) on 

 the surface of the cloacal pouches (posterior nephridia), 6) and less 

 abundantly scattered on the surface of the intestine. The pigment is 

 in the form of granules which are scattered in the cells of the coelomic 

 epithelium where it invests the parts just named. This pigment is not 

 soluble in distilled water and has no relation to Haemoglobin 

 or apparently to any such body, but is comparable to the yellow pig- 

 ment of the coelomic investment of the intestinal wall and large vessels 

 of Lumhricus . 



Besides this orange pigment, it is found that Haemoglobin is pre- 

 sent in certain organs, viz. 



1) The muscles of the middle region of the body are coloured 

 pale-red by Haemoglobin. 



2) The thick coelomic epithelium which covers the numerous 

 mesenterial membranes attached to the intestine and body- wall, is pale 

 red owing to the presence of Haemoglobin. 



3) Similarly the coelomic investment of the genital pouches in 

 the reduced inactive condition which they exhibit in the spring con- 

 tains, in addition to the orange-coloured pigment granules, a consider- 

 able quantity of diffused Haemoglobin which gives a deep crimson 

 tint to these parts. 



The cells of the coelomic epithelium , which are thus found in 

 various regions of the body to contain diffused Haemoglobin, are clear 

 spherical cells with few granules. They contain much less Haemoglobin 

 than the floating corpuscles of the perivisceral liquid but the latter are 

 undoubtedly derived from the former : the fixed haemoglobinous cells 

 at certain places become detached and constitute the floating haemo- 

 globinous cells -whilst acquiring a deeper colour. 



The presence of Haemoglobin in the parts just named was deter- 

 mined by means of the spectroscope namely by the super-position of 

 the spectra of their colouring matter and that of human Haemoglobin. 



