56 K. KISHIXOUYE. 



peculiar and \kivy convenient marks of the .spawn are lost after three or 

 four days. Therefore I fonnd it necessary to dig out eggs as soon as 

 possible after the time of deposition and to transfer them into a large 

 wooden box, especially made for this purpose. The box was filled 

 with sand and was placed at the mouth of a canal. The place was 

 happily chosen as the box was covered by water during high tide and 

 exposed to the air during low tide, and was always exposed to the sun- 

 shine in the day-time. 



In the summer of 1889 I buried eggs of different stages in the 

 box ; but in the year following I buried only two series of spawns 

 which were deposited on the same day, and thus I could easily find 

 out how many days old my eggs were. 



Eggs one or two days old are not spherical but polyhedral by 

 mutual pressure. At this time they are connected together by the 

 coao'ulation of a fluid with wliich thev were covered, when deposited. 

 The averaa'e diameter of an eo'ii' is ^t^ mm. Its volk is vellowish and 

 glutinous ; but when exposed to the air it soon loses water and changes 

 its color to dirty green, and becomes hard, and brittle. It is covered 

 with a thick, tough chorion which with the abundant yolk makes 

 observations either from the surface or by section very troublesome. 



Eo-o's were fixed bv heatino- in water to 60°-70° C, or bv 

 ])]unging into liot water of the same degree. After cooling they were 

 tvaiisierred into 70 7o 'dcohol, in which they were left one or two days, 

 'llien in the case of eggs of early stages some of them were pierced 

 through into the yolk with the point of a fine needle at two or three 

 spots, care being taken not to hurt the germinal disc. These perforated 

 eggs were left in 70 % alcohol for one or two days more, and afterwards 

 were dehydrated in ascending: o'rades of alcohol. The chorion is 

 si)lit naturallv or h\ heating;' and is easilv removed: but at these staoes 

 the vicarious chorion is formed. This mcmbrsine was perforated 



