No. I.] FILOSE ACTIVITY IN METAZOAN EGGS. 



I I 



cell on the opposite side of a narrow cleavage space at the 

 center of the rather compact group of eight cells. 



Such intercellular connections as this would seem to be, in 

 all probability, of the same nature as those seen in live and in 

 preserved echinoderm eggs. And if such be the case, it is 

 especially interesting to find them in Amphioxus, not only as 

 this is in many respects so diagrammatic a representative of 

 the Chordata as to lead one to infer its filose phenomena will 



Fig. 5. 



be found, in modified form, in various vertebrates, but because 

 the egg of Amphioxus has been so carefully studied by experi- 

 mental methods that the need of an organic intercellular con- 

 nection to explain known facts in embryology is here especially 

 felt. Thus Prof. E. B. Wilson was led to conclude in his study 

 of Amphioxus,^ "■ tJiat the unity of the normal embryo is not 

 caused by a mere juxtaposition of the eel Is. . . . This Jinity is 

 not mechanical, but physiological. . . . There must be a struc- 



1 " Amphioxus and the Mosaic Theory of Development," Jou7-7i. of Morph. 

 Vol. viii. 1893. 



