396 
On the Propuction of Spores in the Rapiovaria. By 
Professor L. CreNkowsk1. (With Plate XVIII). 
(Translated from the fourth part of vol. vii (1871) of the ‘Archivjfur Mikroskop. 
Anatomie.’) 
Atmost all that we know of the developmental history of 
the Radiolarians renders it extremely probable that the 
Capsule takes an important part in the reproduction of these 
organisms. Besides the oft observed multiplication of the 
Capsule by division, science possesses some other evidence 
which seems to be of great importance. Joh. Miiller! saw 
in the interior of an Acanthometra a swarming of small 
monad-like vesicles, which moved about for a time, and then 
changed themselves into Actinophrys-like structures. Since 
the subsequent history of these monad-like bodies was not 
made out, the suspicion of the intrusion of some parasitic 
organism could not in this case be set aside. 
Still more in favour of the existence of motile Radiolarian 
germs are the facts brought forward by Haeckel, in his cele- 
brated work.? He saw, firstly, in Spherozoids, the contents 
of the Capsules break up into many vesicles. and, secondly, 
in Spherozoum, he observed masses of vesicles which ex- 
hibited a vibratory movement. What was especially con- 
vincing that these structures belonged really to the Radiolaria, 
was the circumstance that these vesicles contained the same 
wetstone-like crystalline bodies which are seen abundantly 
mixed up in the Capsule contents of the compound Radio- 
laria. Lastly, the groups of amceboid vesicles with movable 
flagellum-like processes observed by Schneider in Thalassi- 
colla Capsules must be mentioned. 
The above observations make it, then, exceedingly pro- 
bable that the Radiolaria reproduce by motile germs which 
are developed from the Capsule contents. 
To the investigation of these phenomena, as also to the 
development of the still questionable yellow cells, were my 
energies chiefly directed, when I had the opportunity, in the 
past winter (January to the middle of March), in Naples and 
Messina, of examining living Radiolaria. It soon became 
apparent that the Acanthometre and the simple Radiolaria, 
e.g., the Aulacantha, so common in Naples, are little suited to 
the investigation. I therefore devoted myself mainly to the 
colony-building forms. I investigated especially Collo- 
sphera and Collozoum. 
The structural relations of the compound Radiolaria are in 
1 « Abhandlungen der Berlin Akademie,’ 1858. 
2 ‘Die Radiolarien,’ pp. 141, 147, Taf. 33, fig. 9; Taf. 35, figs. 11, 12. 
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