22 HISTORY OF THE EGG FROM FERTILIZATION TO CLEAVAGE. 



Eihalfte, bald naher, bald ferner vom Keime, zuweilen lag sie indess am 

 Aequator, zuweilen auch in der untern Eihalfte. Eine griissere Constanz 

 der Lage vermochte ich erst zu constatiren, als ich an die Untersuchung 

 von Eiern ging, welehe unter Ausschluss von Wasser aufgefangen waren. 

 An den unmittelbar der Bauchhiihle entnommenen, nur in BauchhiJhle- 

 tliissigkeit schwiinnienden Eiern fehlt noch die Beweglichkeit der Dotter- 

 kugel innerhalb der Kapsel, beide sind fest zu einander orientirt und zwar 

 so, dass die Mikropyle divas excentrisch uber dan Keime Kegt."* 



The form of the body, doubtfully referred to the spermatozoon, is ex- 

 tremely variable. In a few cases it was not found (Fig. 1). In Fig. 2 

 it is triangular, and contains one or two refractive granules; in Fig. 3 it 

 has an elongated form, containing in one end a conspicuous chromatic ele- 

 ment, to the right of which, in line with what appears to be the 'tail, two 

 less distinct granules are seen. In Fig. 4 the chromatic corpuscle lies 

 a little nearer the spindle than the micropyle, and close to the left of it is an 

 irregular angular space, in which are some granules. Sometimes this body 

 (Figs. 5, G) appears to be double, and lies in a clear space, the whole being 

 distinguishable from the spindle and its clear area only by close examination. 

 In Fig. 7, the shape approaches more nearly that of a spermatozoon. 



The spermatic body always lies at the outer surface of the ovum, and 

 is difficult to find in sections. It has been possible to identify it (Fig. 9), 

 but we have failed to get any sections that would throw light on its 

 structure. 



/3. The Polar Spindles. — As the first two nuclear spindles give origin 

 to the polar globules, we may conveniently designate them as polar 

 spindles. This name seems to us more appropriate than direction spindle, 

 and to be entirely free from the objections that weigh against the latter. 

 It is less cumbersome than maturation spindle, serves equally well to dis- 

 tinguish them from the cleavage spindles, and carries no implication as 

 to their significance. 



It is currently stated that these spindles mark the germinative polo ; 

 but, as a glance at Plates XXII. and XXIII. will show, it is more than 

 doubtful if this view can be allowed to pass unchallenged. In eggs 

 fertilized under natural conditions, the polar globules are generally found 



* As tlic existence of pore-canals in the- membrane of these eggs lias boon denied, it may be well to 

 state here, that we have found no trouble in recognizing them in surface preparations. They appear to be 

 larger in the neighborhood of the micropyle than elsewhere | Figs. 3-9, PI. XXII.). 



