Eisen, The Chrouioplasts and the Chromioles. 



3. 



135 



chromoplasta 



nucleus 



lenders 



3. The two chrouioplasts are connected with 6 leaders each. Each leader is 

 made up of 6 chrornomeres with 6 chromioles each. Linin and lininoplasts 



not figured. 



chromoplast 



chromoplast 



contractile 



beodid 

 spindle fibres 



chroinomere 

 'with fi chro- 

 mioles each 



}- chroinomere with 

 6 chromioles each 



4. Split chromosome just before being seperated into two doughter chromo- 



somes. 



5. A chromosome just after separation from its sister chromosome. Chromo- 

 plast attatched to the limb. Beaded contractile fibre at the angle of the 



two arms. 



Finally, a word regarding- the technique. It is useless to endea- 

 vor to study these minute bodies without the aid of the very best 

 optical appliances possible, and with the most careful treatment of 

 the material. A Zeiss - - or equally good - - Aiiochromate of 2 mm, 

 with an Aperture of 1.40, is an absolute necessity. A lesser apperture 

 will not suffice. Moreover an oil immersion condenser in the substage 

 must be used, the common Abbe condensers do not give a sufficiently 

 perfect light to enable one to see the necessary details. And lastly, 

 the ordinary daylight is not suitable, being neither sufficiently pure, 

 nor steady enough to always give the same results. In these investi- 

 gations I have used exclusively the achromatic light -filter described 



