nindo out. Scarcli for cells showing the nucleus in the 

 monaster, metakinetic, and diaster stages. Sketch a rest- 

 ing nucleus, and the various stages of division seen in 

 your section. 



(c) Large Animal Cells. 



The (iviiiy of a very yoiui'icliirken was hanleiieii in a SMtura'ed 

 aqiiedus solution of hiclilmide of mercury, stained en masse in borax 

 carmine, eml)edi]ed in paraflin. ami soclioiu'd. 



All paraffin sections are to he mounted in tlic following 

 way: — Bring to the distrilmting tahle a slide on which a 

 tliin layer of allximen fixative (equal parts of white of 

 egg and glycerine) has l)een spread. The ])arafHii section 

 will then he fixed to the slide. Then hold the slide over a 

 gas flame until the paraffin begins to melt, next drop a few 

 drops of turpentine on the section, and at the same time 

 rock the slide l)ackward and forward until the paraffin has 

 been dissolved. \Vi})e away the excess of turpentine, add 

 a small drop of l)alsam, and cover with a cover glass. 



Study under low power. Observe the large round cells, 

 some of which show a relative!}' large nucleus. Sketch 

 several as seen under low jjower. 



(d) Karyokinesis in Animal Cells. 



The testes of a salamander are to be removed from the animal 

 during tbe month of June. They were cut into small pieces, liardened 

 •7n.l in rieming's or Hermann's solution, embedded in j)araftin, very thin 

 ' sections cut and fixed to cover glasses, and stained either in safranin 



and licht grim oi Ilaidenliain'.s ii-on-lack-hsematoxyiiii and acid 

 fucli.sin. A fterstaining,t lie sections were dehydrated, i)assed throuudi 

 oil of bergamot into xylol, from which they are mounted. Come to 

 the table with a small drop of balsam on your slide. 



Study the section first under low power, and you will 

 observe that the cells are arranged in lar<:er and smaller 

 nests. Under high power groups of cells in mitotic cell 

 division are often met with. All the cells in such a group 

 usually present about the same stage of division. Search 

 the section thoroughly until all the stages have been seen 

 and sketched. 



