STUDIES OP REPEODUCTIYE ELEME^TS : II. ^^9 



])ect, an intermediate staa'e, so to speak, between the Metazoa and 

 other Prot o z o a . If in E n g I y p li a a I v e o 1 a t a the Polkörperchen is 

 formed from the nuclear substance and l^ecomes connected with the 

 cytoplasm during the nuclear division, to be again withdrawn into 

 the nucleus, it forms in tliat case an interesting connecting hnk between 

 Leptodiscus and Xoctiliica! But we must confine ourselves to 

 facts only. 



Another interesting tiling about the Noctiluca archoplasm is 

 its extreme similarity with the Neheuh'rii of vo)t la Valette Si. George 

 (13, U\ and riatNer (29). Just like the archoplasm ofNoctiluca, 

 the NerenkerH of these authors is formed by the consolidation of a 

 part of the cytoplasjn at one side of the nucleus, and wlieu this be- 

 comes visible the '^ Schleifenbiindel des Kerns ist stets mit der Spitze 

 gegen jene Verdichtiuig hingerichtet" (Ay l'alette 13, ]). 7). The 

 ])art ])layed by tlie Xemil-ern ap])ears, however, not (juite clear, but 

 roN la \ (dette St. (leonje considers it very })robable that the spindle 

 fibres are formed from its elements in lîlatta, since these transform 

 again to fi^rm fhe Xelteukern (13, ]>. 10). AVhen tliis fact is ])roved, 

 then tlie parallelism between the Noctilnca archoplasm and the 

 Nebenkern, of run la Valette St. Geonje will be proved l)ev<^nd all doubt. 

 It will not be, however, a rash conclusion to consider these two ])odies 

 as identical, especially when we consider the fate of the Nehenkern in 

 the foi-matioH of tlie spermatozoa, as will be seen later on. The 

 close similarity l)etween the two will also be seen by com])aring von la 

 Valette s F\g. (J on Plate 111 <)f '' /vö7///.vr'.s Festschrift, 18 <S7 '' with 

 ray Figs. 1, 2, 6, or 7. 



Of not less interest tlian the archoplasm is the origin of tlie spindle- 

 fibres. Two different opinions are here also to be met with as in the. 

 case of the origin of the kinetic centre. Str((s]nir(jer in his earlier 

 works (33, 34) as well as in his newest (35, p. 59-62). has shown in 



