Echinoderma. 



that it passes into Tiedemann s bodies, the central cells of which become thickly 

 crowded with it and the peripheral ones less so, while those of the ovoid gland are 

 unaffected. Tiedeniann's bodies are also strongly coloured by similar injections 

 of Bismarck brown, cells impregnated with it appearing in great numbers on the 

 surface, as if passing from the water-vessels into the body cavity. But injections 

 into the body cavity do not colour Tiedemann' s bodies, which seem to be the ex- 

 cretory organs of the water-vascular system. The ovoid gland of Urchins 

 becomes impregnated with carmine which is injected into the body cavity, of which 

 it serves as the excretory organ. It sometimes undergoes repeated, though not 

 regular contractions. Tiedemann's bodies and the ovoid gland of Echinoderms 

 thus appear to have the same relation as the segmental organs of most Annelids, 

 that is, they excrete carmine, and have a slight acid reaction. 



Cuenot has published a preliminary account of his extended studies of the blood 

 corpuscles of Invertebrates. Those relating to Stellerids were noticed in the Be- 

 richt for 1888 Ech. p 13, 17. The amoebocytes in the perivisceral fluid of 

 Urchins are formed by the ovoid gland and Polian vesicles, which are lymphatic 

 glands and not excretory organs, as supposed by Hartog and the cousins Sarasin 

 [see Bericht for 1887 Ech. p 3 and 1888 Ech. p 22]. The newly formed amoe- 

 bocytes are at first colourless or contain yellow granules which occur elsewhere 

 in the body and may be either excrementitious or reserve material. Some become 

 filled with proteid granules, draw in their pseudopodia, and are known as the 

 mulberry-corpuscles. Others accumulate brown granules of a reserve fatty sub- 

 stance, the echinochrome of Mac Munn. These two last forms of corpuscles pass 

 by diapedesis into the tissues and serve for their nutrition. The only lymphatic 

 gland in the Crinoids is the ovoid gland, and the body cavity contains normal 

 amoebocytes with the albuminogenous ferment, many of them filled with yellow 

 proteid granules. These reserve amoebocytes are absent in the Stellerids, the 

 perivisceral liquid containing a quantity of albuminoids in solution, but they occur 

 in Holothurians, together with those containing yellow granules, as in Urchins 

 and Crinoids. In all the Echinoderms which have an ovoid gland it is in relation 

 with the genitalia, and the sexual products are formed from lymphatic cells. 



Mac Munn (S 2 ) finds that there is no evidence of the presence of chlorophyll 

 in the sacculi of Antedon rosacea, which were supposed by Vogt & Yung to 

 contain the zoospores of symbiotic Algae [see Bericht for 1886 Ech. p 6]. The 

 chlorophyll found by Krukenberg in this type belongs to the contents of the sto- 

 mach, and is not an enterochlorophyll due to a liver. The intrinsic colouring 

 matter of A. rosacea differs from the antedonin found by Moseley in certain 

 tropical Comatulae ; but something like it occurs in other species, while altered 

 antedonin was found in two species of Actinometra. The ovaries of Holothuria 

 nigra contain two lipochromes, one resembling xanthophan, the other rhodo- 

 phan. The latter is built up in the digestive gland, and is thence carried off by 

 the blood current to the integument and ovaries. The integument also contains 

 Krukenberg's u ran id in, which is, however, quite different from the similarly 

 named pigment in sponges. The Polian vesicle of H. nigra contains a lipo- 

 chromogen, and there is a similar substance in the blue ovaries of Ocnus 

 brunneus, which becomes changed into a reddish lipochrome under very slight 

 influences. The integument of Aster las glacialis contains at least one rhodophan- 

 like lipochrome, but no haeniatoporphyrin. The same lipochrome occurs in the 

 hepatic caeca, together with enterochlorophyll. The latter substance is present 

 in Goniaster, Solaster, and Asterina, in which, as in several other Echinoderms, 

 its yellow or red lipochrome -constituent is built up in the digestive gland 

 and thence carried to the integument and ovaries. The digestive gland thus 



