9 



The second -^lanr of divisior^ id also n^oridional and 

 at riPht anp:ler; to the first. This '^leavafjr takfis nlaco 

 about fifteen -inuter- after the first divisio-. Those 

 secor^d soFT-entation furrows start ^t the centre ?.no -ove 

 out toward/the periphery. Durin,? their progress outward 

 there are to be seen globular or oval snaces at their cuter 

 extrcTities. These spaces are large enough to cause open- 

 ings that exterd through the egg as shov/n in Firure 7. 

 During this cleavage there is a shifti-g or rctatio- of the 

 blastor-errs fro^ right to left. The second seg-^entaior. fur- 

 rcr.'s usually start op'-osite each other at a point in the 

 centre of the first cleevage furrow, and then arc carried 

 apart by the rotatio":. Or the rotation Ty heve started 

 before the second segTentatior began; in that case the second 

 cleavage '•lares are soT.e distance apart -s soon as they 

 make their appearance. Figure 7 shov.'s on egr in the '^re- 

 cess of divisir^ in which rotation has taken Place, During 

 the progress of the second seg-entation , the ep.f^ hns fre- 



