548 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
secondarily acquire another significance. But this is only a very 
general indication of the conclusions reached in this interesting paper, 
which, though very speculative, is also full of concreteness. 
Conjugation and Karyokinesis in Actinosphserium.* * * § — Prof. R. 
Hertwig first describes the processes which precede encystation, corro- 
borating Brauer, except that' the latter thought the nuclei were reduced 
in number by fusion, while Hertwig thinks they dissolve. However it 
is effected, the number is reduced to about 1/50. Round each remain- 
ing nucleus a ‘'primary cyst” is formed; the nucleus of each of these 
divides by mitosis, and the “ secondary cysts ” are formed. The nuclei 
of the secondary cysts then divide twice in succession by mitosis, and 
each time one daughter-nucleus is thrown off as if it were a polar kody ; 
then the two associated cysts fuse, nucleus with nucleus and plasm with 
plasm. It seems an extreme case of autogamy, and can only be of use 
in bringing about a reconstruction of the nuclear material. The karyo- 
kinesis concerned in the getting rid of the polar bodies is “ heteropolar,” 
and differs also from the ordinary mitosis of Actinosphserium in the 
presence of a centrosome. 
Fossil Radiolarians.f — Sig. P. E. Vinassa de Regny gives a list of 
109 fossil Radiolarians from the“ftaniti titoniane ” of Carpena near 
Spezia. Of the 109 only 13 have been previously recorded as fossils. 
The abundance of Spheeridea and Cyrtidea is remarkable. Several 
genera, e. g. Spongolonche , Exastylarium, Pipetella, Tripodictya , and 
Carpocanistrum , are for the first time recognised as being represented 
in fossil form. 
Peneroplis.t — Herr F. Dreyer has made this Foraminifer (P. pertusus) 
tlie basis of a discussion of morphological principles and the question 
of species. He deals with the variations observed in about 25,000 
specimens, — a broad basis for induction. It is by studies of actual 
facts, he says, and not by phylogenetic speculation, that progress will 
be made. The selection theory is false ; and even if it were true, it does 
not touch the heart of the problem. “Wenn sie rich tig ware, ware 
sie nichtig.” It is time that biology should try to recover from “ its 
English disease ” ! 
Hew Infusorian Genus.§— R. Sand describes Nematopoda cylindrica 
g. et sp. n., a new Peritrichous Infusorian found on algas at Roscoff. 
The new genus resembles Gothurnia , but it is the only member of the 
Dexiotricha which has both a case and a stalk. It is also the only 
genus in which the contractile stalk consists of a single undifferentiated 
filament. 
* SB. Ges. Morpli. Munchen, xii. (1897) pp. 83-90, and xiii. pp. 36-41. See 
Zool. Centralbl., v. (1898) pp. 394-6. 
t Atti R. Accad. Lincei (Rend.), vii. (1898) pp. 34-9. 
X ‘ Peneroplis. Eine Studie zur biologischen Morphologie und zur Speciesfra^e ’ 
Leipzig, 1898, 4to, 119 pp., 5 pis. See Zool. Centralbl., v. (189«) pp. 357-64. ° ’ 
§ Ann. Soc. Beige Micr., xxii, (1898) pp. 85-99 (6 figs.). 
