386 ANDREWS. [Vou. XII. 
Mature and properly fertilized eggs when heated too much 
or kept too closely confined, cease their normal, delicate spinning 
to burst into profuse transpositions of their substance, which 
may cause even considerable distortion of their form, or, accord- 
ing to the degree of abnormality produced, may be visible only 
as excess of the usual processes. If not too much affected, such 
slight abnormalities may be cured and the perfect larva form as 
usual. 
If the adverse conditions are continued, such eggs often cease 
from all further cell division and exhaust their powers in perfect 
orgies of spinnings, as just described for abnormal eggs. 
Protoplasm artificially pressed from normal starfish eggs in 
early stages spins characteristically like abnormal unruptured 
eggs and cells, not like those in normal condition. Such 
activities varied also their quantity and character in correlation 
with certain rhythms of difference of physical quality which 
marked the living substance during development of both star- 
fish and Echinus eggs. These rhythms are treated of in the 
forthcoming essay mentioned above. 
There was every optical evidence of actual interchange of 
substance by the cells of developing starfish eggs and also 
Echinus eggs by way of the filose processes; for a procession 
of granules along a filament for some moments in one direc- 
tion, sometimes ended by abrupt withdrawal of the filament. 
Whether these granules returned later along some other fila- 
ment could not of course be determined ; but even so, they 
would have been for a time inhabitants of the cell in which 
they were left, and so also would the substance of whose pass- 
ing they were clearest indications. 
A most noteworthy thing was made plain by this series of 
observations. The vesicular structure of Biitschli, and that 
modification of it termed by him the “alveolar layer,” clearly 
traceable under favorable optical conditions in these eggs, exists 
and remains optically undisturbed for moments at a time during 
such peripheral activities as can drain the egg of considerable 
amounts of its substance, yet pass undetected under the 
powers which have been commonly used for observing develop- 
mental phenomena. 
