THE ORGANIZATION AND EARLY DEVELOPMENT 

 OF THE EGG OF CLAVA LEPTOSTYLA AG. 



CHAS. W. HARGITT.' 



A recent paper by Harm ('02), on the development of Clava 

 sqnamata describes several features so unlike conditions which I 

 have found in the American species, that it has seemed worth 

 while to study anew, and in some detail, the entire life history, 

 including also some interesting peculiarities of the organization 

 of the egg not hitherto given any degree of attention among 

 ccelenterates. 



The general facts concerning the morphology, habits, etc., of 

 Clava leptostyla Ag. were described long ago by Professor Agas- 

 siz ('62) with sufficient fulness to obviate the necessity of any 

 considerable details as to these points. Allman ('71) has likewise 

 given a somewhat similar account of C. sqnamata, though lacking 

 in embryological details. 



The following account is based upon studies carried on at 

 Woods Holl during some two summers, chiefly upon living ma- 

 terial, though for the details of cytology specimens were killed 

 by several standard methods, among which were corrosive-acetic 

 acid, picro-acetic, Carnoy's solution, Petrunkevitch solution, and 

 corrosive formalin. Upon the whole, the first two of the reagents 

 named gave by far the better fixation. As will be noted in an- 

 other connection, for certain cytological results the picro-acetic 

 solution was exceptionally good. 



The most common habitat of the species in this vicinity was 

 found to be the fronds of the common rock-weed, Fnciis nodosns. 

 Occasionally I have taken it from the piles of docks, or similar 

 situations. It occurs most frequently in shallower harbors, or 

 tide-pools, and is frequently found at low tide quite exposed, ex- 

 cept as the moist vegetation may afford a measure of protection, 

 lying thus for hours subject to the desiccating influences of sun 

 and air, and apparently without serious injury. Of course, this 



1 Contributions from the Zoological Laboratory, Syracuse University. 



207 



