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diesem zum Vorschein. Beide bestehen aus Biischeln sehr kleiner, 
länglicher Lobuli, welche an Blutgefäßen hängen und durch lockeres 
Bindegewebe zusammengehalten werden. Jeder Lobulus besteht aus 
einer doppelten Reihe von cylindrischen, kernhaltigen Zellen, welche 
Reihen am Ende des zottenförmigen Lobulus in einander umbiegen. 
Zwischen diesen beiden Reihen verlaufen die Gefäße und ein Strang 
von Bindegewebe.” In a foot-note he says: “Bei den Myxinoiden ist 
dies Gebilde aufgefunden und beschrieben von J. MÜLLER, der es zuerst 
als Nebenniere, später als Thymus deutete.” 
WILHELM MULLER!) in 1875 described the pronephros in young 
Myxine, but makes no mention of any structures of the nature of 
suprarenal bodies. 
WELDON ?) in 1884 described the head-kidney in Bdellostoma; 
as Dr. Vincent has recently?) dealt with this paper, we would 
therefore simply say that weldon states that in Bdellostoma 
there is “in front of the kidney proper .. on each side, a small, 
lobulated, apparently glandular body”, which he suggests is “a part 
of the embryonic kidney, modified in connection with the needs 
of the animal, to perform some unknown function in the elaboration 
or purification of the blood”. (!) Instancing BALFOUR’s account of 
the lymphatic nature of the head kidney in Teleostei and Lepid- 
osteus as such a modification, he writes: “This being the case, the 
question arises whether there may not exist, in all vertebrate animals, 
similarly modified portions of the primitive kidney. I believe that 
such structures are, as a matter of fact, to be found in 
the suprarenal bodies’ *). 
Whether Professor WELDON still holds these views we cannot say, 
but a knowledge of these structures in the Lower Vertebrates cer- 
tainly does not support such views, and we shall endeavour to show 
that, as yet, there is no evidence on record of any case where the 
head-kidney has in any sense replaced the suprarenal bodies. 
In a later paper he writes5) (p. 147): “In Bdellostoma, I 
have already attempted to show®) that the head-kidney has be- 
come modified so as to form an organ functionally analogous to the 
suprarenals.” 
1) Jen. Zeitschr., Bd. 9, 1875, p. 94—129, Taf. 4—5. 
2) Quart. Journ. Micr. Sc., 1884, Vol. 24, p. 171—182, Pl. 15. 
3) Trans. Zool. Soc., 1897 (in ee press). 
4) The italics are Professor Wxınon’s. Professor WELDON omits to 
mention that this view was put forward by RATHkE in 1827. 
5) Quart. Journ. Micr. Sc., 1885, Vol. 25. 
6) The italics are ours. 
