352 W. E. HOY, JR. 



24 is only approximate. Taking Miss Stevens's results as a 

 standard this number would seem to indicate a number of 

 chromosomes in somatic cells corresponding to the haploid 

 number in the germ cells. 



Vom Rath's observations on the dog were made on a three 

 weeks' old animal. He qualifies his remarks with the statement 

 that owing to the small size of the chromosomes he was able to 

 make only an approximate enumeration. In addition to the 

 variations in the blood cells and the bladder he found great 

 variation in the spleen, the bone marrow and in the testis. He 

 considers 32 as the typical number, and points out that this 

 number, together with the variations, is a multiple of eight, 

 which number he also found, thus showing that the chromosomes 

 may be bivalent, quadrivalent, or even polyvalent. The fact 

 that he frequently found multipolar mitoses seems to indicate 

 that his material may have been abnormal. 



The observations of Winiwarter and Sainmont on the cat are 

 comparable to those of the former on the rabbit. The probability 

 here is that there is a breaking up of the chromosomes in the 

 somatic cells. 



Vom Rath considers the chromosomes in the somatic tissues 

 of Salamandra as bivalent. However, his statement "hatte ich 

 . . . mit absoluter Sicherheit nur 12 Schleifen (Aequator 24) 

 gefunden" is not clear. Rabl and Meves conclude that chromo- 

 some pairs cannot be distinguished in the somatic cells. Delia 

 Valle, as a result of finding a chromosome number of between 

 19 and 27, considers the number variable and the chromosomes 

 as temporary and variable organizations of chromatin, which 

 appear in the prophase and dissolve in the telophase. The 

 number of the chromosomes is simply the quotient of the quantity 

 of the chromatin. 



Mack states that the number of chromosomes in the somatic 

 cells of Amblystoma agrees with the number in the primary 

 spermatocytes. Jenkinson merely states that his observations 

 are not in accord with those of Fick and Kolliker. 



With reference to Murray's count of 36 chromosomes in Lepido- 

 siren Agar says (p. 5): "Murray gave the somatic number as 

 probably thirty-six, which is as near the right number as could 



