No. I.] FILOSE ACTIVITY IN METAZOAN EGGS. 5 



features, this was decided not to be a case of filose activity. 

 In the same &^g some shorter, slender pseudopodia projected 

 from one cell, but could not be traced more than a tenth of 

 the distance to the opposite cell toward which they extended 

 over the above-mentioned polar space. 



The most delicate filose displays were seen near the polar 

 bodies during the first and second cleavages. The ^^g put 

 forth fine protoplasmic threads that branched and reached up 

 toward the second polar body. In this region a sheet of sub- 

 stance connected the ^gg with the second polar body, and the 

 filose phenomena in it led to the assumption that it was a flow- 

 ing mass of protoplasm, or that it contained more or less of it. 

 But this, with the remarkable filose activities of the polar bodies, 

 has been described and figured elsewhere.^ In both a gastero- 

 pod and a lamellibranch, the polar bodies were likewise seen to 

 have filose activities.^ Thus in several great groups of animals 

 the polar bodies may act in a filose way for some time after 

 their extrusion, plainly exhibiting contractile phenomena in 

 their cytoplasm and showing themselves to be still alive and 

 active, so that, whatever may be their import as regards the 

 chromatin they carry with them, they appear as more or less 

 isolated parts of the egg mass, carrying on filose changes of 

 the same nature as those of its other parts. 



Being convinced that filose phenomena essentially similar to 

 those of certain Protozoa exist also in the great metazoan 

 groups Echinodermata, Annelida, Mollusca, and Nemertina, 

 another attempt was made to find them in Chordata by study- 

 ing some preserved Amphioxus eggs. However, the relation 

 between living and preserved material is so remote in cases of 

 such delicate phenomena as these sought, that little weight 

 could be laid upon the results without a knowledge of the live 

 eggs. Lacking this, it was thought that an acquaintance with 

 the live and the preserved eggs of echinoderms would suffice 

 to enable one to draw tentative conclusions from the preserved 



1 Andrews, E. A., "Activities of the Polar Bodies of Cerebratulus," Archiv. f. 

 Entwickhiitgsmechanik. Bd. vi. 1898. 



-Andrews, E. A., "Some Activities of Polar Bodies," _/(?/i;« Hopkins Univer- 

 sity Circulars. Vol. xvii, No. 132. November, 1S97. 



