98 Colchicine 



First signs of partial spindles were seen at 48 hours. This is evi- 

 dence that recovery or reversibility was taking full effect, so that by 

 72 hours a complete spindle was reformed. 



Reversibility is seen in animal cells, but the recovery is complicated 

 by other effects in addition to arrested mitosis. This is particularly 

 true in mannnals, where considerable destruction of arrested meta- 

 jjhases takes place not gi\ing time tor the spindle to recover before 

 the chromosomes are irreversibly altered. 



3.9: Summary 



In this chapter and in the preceding one, selected works were cor- 

 related to describe, first, the action ujjon nuclear mitosis as obser\ed 

 through chromosomal patterns and, second, the spindle mechanisms 

 fundamental to arrest by various techniques, ^\^e are aware that little 

 attention was given to the mechanism of action, theoretical aspects, 

 and problems of c-mitosis, all of which are suggested by the data. 



The action of colchicine involves the cell as a whole and, for ani- 

 mals, the correlated activity of tissues. Before a discussion of the prob- 

 lems can be made most effectively, other aspects must be viewed. 

 Therefore the mechanisms of action as well as the very im])ortant 

 problem of mitotic poisons are grouped together in Chapter 17. Here 

 it is hoped that some of the important issues raised by the action of 

 colchicine on jjlant and animal cells can be brought into a synthesis, 

 the problcuis of c-mitosis. 



REFERENCES 



1. Allen, E.. Smith, G., and Gardner, \\ . Accentuation of the growth effect of 

 theelin on genital tissues by arrest of mitosis with colchicine. Anat. Rec. 67: 

 Suppl. 1:49. 1936. Accentuation of the growth effect of theelin on genital tissues 

 of tlie o\ariectomizetl mouse, bv arrest of mitosis with colchicine. Amer. Jour. 

 Anat. 61:321-41. 1937. 



2. Barber, H., and Callan, H. (see Ref. No. 1, Chap. 2. 1943) . 



3. Barigozzl C. (see Ref. No. 2, Chap. 2. 1942) . 



4. . and Fantoni, L. (see Ref. No. 3, Chap. 2. 1942) . 



5. Beams, H., and Evans, T. (see Ref. No. 4, Chap. 2. 1940) . 

 0. , AND King, R. (see Ref. No. 5, Chap. 2. 1938) . 



7. Berger, C, and Witkus, E. (see Ref. No. 7, Chap. 2. 1943) . 



8. Bergner, a. (see Ref. No. 8, Chap. 2. 1950) . 



9. Bhaduri, p. (see Ref. No. 9, Chap. 2. 1939, 1940) . 



10. Boas, F., and Gistl, R. Uber einigc Colchiciiiwirkungen. Protoplasma. 

 33:301-10. 1939. 



11. Bram, a. Zum Verhalten der Mitochondrien bei Einwirkung verschiedener 

 Pharmaka. .Acta Anat. 13:385-402. 1951. 



12. Brock, N., Druckrey, H., and Herken, H. L'ber Kerngifte und Cvtoplasmagifte. 

 Arch. Exp. Path. 193:679-87. 1939. 



13. Brodersen, H. Mitosegifte und ionisierende Strahhmg. Stiahlcnther. 73:196- 

 254. 1943. 



11. Brles, a. (see Ref. No. 11, C.hap. 2. 1951) . 



15. , AND Cohen, A. (see Ref. No. 12, Chap. 2. 1936) . 



