198 



Franz Eilharu Schulze: Hexactinelliden. 



feinkörnigen Plasma einen hellen Kern mit einem kleinen, aber stark lichtbrechenden Kern- 

 körperchen zeigen. 



Von der Mitte der im allgemeinen quer abgestutzten freien Endf Lache des Zellkörpers 

 entspringt eine einzige lange Geißel, und von dem Außenrande dieser nahezu kreisrunden End- 

 fläche erhebt sich eine als „Collare" bezeichnete, dünne, hyaline, röhrenförmige Membran, welche 

 quer abgestutzt mit glattem Rande endet. Die cylindrischen Zellkörper stehen bald isoliert 

 nebeneinander, bald liegen sie dicht aneinander. So sagt z. B. Minchin von der Asconen- 

 Gattung C/atkrina 1 ): „In their natural position the collar cells are in close contact, their limits 

 forming in surface view a network of polygonal areas." 



Die erste Nachricht von den Kammerzellen der Hexactinelliden konnte ich im Jahre 

 1880") nach Untersuchung eines in Alkohol absolutus leidlich gut konservierten Exemplares von 

 Euplectella aspergillum Owen geben, welches mir Wyv. Thompson aus den Schätzen der 

 „Challenger"-Expedition anvertraut hatte. Ich habe damals als Ergebnis meiner Untersuchung 

 folgendes angegeben: „I could perceive all the cells in the form of aggerated roundish lumps, 

 in the centre of vvhich a sphaerical nucleus, furnished with a smaller strongly refractive nuclear 

 corpuscle (like that which appears in the collar-cells of other sponges), was sharply defined by 

 means of a tinging medium. If, therefore, nothing was be observed in my preparations of the 

 cylindrical form of the cells, of the peculiar collar-like process, of the collar, or of the flagellum 

 which appears in the collar-cells of other sponges, it by no means follows that they are wanting 

 in the living animal. The fact, that in this case the cells of the ciliated Chambers do not touch 

 each other immediately laterall} r , but lie apart at nearly equal distances, did not surprise me, as 

 I had occasionally found the same in other sponges - - for example, in Spongelia — in pieces 

 which had not been quite sufficiently hardened for examination. On the other hand, the peculiar 

 arrangement and lateral connection of the cells with each other seemed to me highly remarkable. 



Even under a comparatively low magnifying power we can see a reticulate arrangement 

 in the ciliated Chambers, which has never yet been described in any other sponge. 



The cells, which are arranged in spiral or oblique rows, and lie somewhat apart, are 

 connected in such a way by tolerably strong refractive straight cords, that rhomboidal quadrate 

 meshes are formed which are usually of nearly equal size, and only here and there become 

 varied in form and arrangement by the pores of the Chambers. While usually four such lateral 

 connecting cords, forming a straight or oblique cross, proceed to the adjacent cells, there are 

 not rarely five or six such processes. I could not find any complete explanation of the nature 

 of these connecting cords and their relation to the cells; but I believe we must consider them 

 as connecting bridges between the viscid cell bodies". 



Im Jahre 1887 habe ich dann im Challenger-Report, Hexactinellida, p. 23 u. 24 jene 

 Angaben auf Grund etwas weiter ausgedehnter Untersuchung verschiedener Arten wiederholt, 

 ohne etwas wesentlich Neues hinzufügen zu können. 



Letzteres ist mir erst möglich geworden im Jahre [899, als ich von einem unmittelbar 

 nach dem Heraufholen von dem Grunde der Nansenrinne, nördlich von Spitzbergen, in 81" 20' N.Br. 



1) Quarterly Journ. of micr. Sc, i s<»S, Vol. XI.. |>. 47N. 



2) Transact. Roy. Soc. Edinburgh, Vol. XXIX, [880, p. 671. 



