6 MAROUS M. HARTOG. 
Memorrs— 
“Sur la Multiplication des Infusoires ciliés,’ Maupas, in ‘Arch. de 
Zool. Exp.,’ 1888. 
“Le Rajeunissement karyogamique chez les Ciliés,’ Maupas, in ‘ Arch. 
de Zool. Exp.,’ 1889. 
*Karyokinesis and Fertilisation,” Part II, Waldeyer (Engl. Trans.), 
in ‘Quart. Journ. Mier. Sci.,’ Dec., 1889. 
* Vergleich der Hi- und Samenbildung bei Nematoden,” O. Hertwig, in 
‘Arch. f. mikr. Anat.,’ vol. xxxvi, 1890. 
In my terminology I have used the word gamete to designate 
a cell which fuses with another, cytoplast with cytoplast and 
nucleus with nucleus, and zy gote for the cell produced by their 
union; pronucleus and gametonucleus, indifferently, to 
denote the nucleus of a gamete, without any connotation of 
imperfection; gametogonium and progamete to express, 
from slightly different points of view, a cell which divides to 
form gametes or (rarely) passes into the state of a gamete ; 
spermatogonium! and oogonium, spermatogamete and 
oogamete for male or female gametogonia and gametes 
respectively: facultative and obligatory gametes are dis- 
criminated according as they retain the primitive cell privi- 
lege of multiplying by fission (independent of karyogamy) or 
have lost it altogether. I use the phrase gametangium for 
the apocytial chamber in which gametes are developed. Cyto- 
plast designates the cytoplasm considered as a unit in contrast 
to the nucleus. 
By apocytium I mean a mass of protoplasm which is 
habitually plurinucleate, cell division remaining in abey- 
ance; apocytial plants may be continuous; or septate by 
partitions, which always, however, separate multinucleate 
masses of protoplasm. Apocytial structures which unite 
like gametes are termed gametoids, and the product of 
their union a zygotoid. I have freely used Maupas’s ad- 
mirable term karyogamy to comprise all forms of union of 
gametes involving fusion of their nuclei, since fertilisation 
and fecundation are altogether inappropriate to cases of 
‘ Corresponding with the ‘‘spermatospore” of Blomfield, not necessarily 
the “‘spermatogonium ” of La Valette St, George. 
