40 



Colchicine 



TABLE 2.2 

 Arrested Met.^phases — Treatment and Recovery , 

 I. Colchicine Treatment .Study: Triton vulgaris; Epidermal Cells of L.\rv.\e 



(After Barber and Callan, 1943) 



Frequency of Different Types of Cell (Means of Counts From 3 Larvae) 



Differential Count Expressing Percentage of Mitotic Types During Recovery 



were among the first cases known, -^ less exact knowledge oi their 

 formation is at hand than ior the star metaphase. 



Outside the star or the distorted star, isolated chromosomes are 

 regularly observed. This iormation accounts for "lost" chromosomes 

 frequently described in plant and animal tissue-culture cells. !■''• '^" 



2.4-y. Uiioriented metaphases. Chromosomes scattered in the 

 cytoplasm after a nuclear membrane disappears have been thoroughly 

 described in plants^-- ■^^- ^''^ "•^- 5'^' ~'^'- •'*'^' -"• '^•^- ^O' "■5- •■'• '"'■ --• ^'^ and ani- 

 mals.-«- •'^- "-■ ^■'- -'^- •^-- «'• "'»• ^- ""• 28, 53, 39 xhe descriptive expression ex- 

 ploded III rl a phase is appropriate (Figs. 2.4D, 2.1 A, and 2.8^4) . There 



