First report on the cytological investigation of cancer : 1906 / by J.E.S. Moore and C.E. Walker.

  • Moore, J. E. S.
Date:
[1906]
Catalogue details

Licence: In copyright

Credit: First report on the cytological investigation of cancer : 1906 / by J.E.S. Moore and C.E. Walker. Source: Wellcome Collection.

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    Man Rat Triton, sp. Cockroach Diagram showing the Forms of Heterolytic Gemini in various Animals. Total number Total number of gemini. of gemini. Man ... ... ... ... ... 16 Triton, s.p. ... ... ... ... 12 Rat ... ... ... ... ... 16 Cockroach ... ... ... ... 16 The above results, based upon a study of the gemini in the first maiotic divisions in Triton, are interesting in themselves, but they immediately raise the further question as to whether the order here observed is simply a curious instance, or an individual expression of a wider law; on account of this we have studied in a similar manner the first maiotic division in man, rats, and Periplaneta\ that is to say, in two more typical vertebrates and a representative arthropod. In the testis of rats the first maiotic division occurs in groups of cells, and it is by no means difficult to bring under observation in a short time thirty or forty instances of the early spindle and late prophase. \n this we have material amply sufficient to arrive at a decision upon the matters with which we are concerned. Fig. 3 is a drawing of a portion of a tubule from the testis of a piebald rat. It shows the outer wall of the tubule with some pre-maiotic nuclei and three dividing cells belonging to the first maiotic (heterotype) mitosis. In these it will be seen that the gemini are of very different forms, and that as in Triton the same forms are repeated in different individual cells. Analysis of a large number of similar cells reveals the fact that in this particular example there are again six varieties of gemini (see table, page ). In the rat, however, instead of the pre-maiotic chromosomes being 24 in number as in Triton, there are 32; consequently we shall have to ascertain the relative numbers of the different types. Further it will be seen that the six types present in the rat are not all the same as those catalogued for Triton (table, p. ). It will indeed be obvious from this that only four of the Amphibian varieties are represented in the mammal; to these four two new forms of gemini are added.