(1) The frequency of primary exceptions in D. virilis is about 1:1000; that is somewhat higher than that in D. melanogaster (1:2000). The frequency of primary exceptional females is much lower than that of the males, being 1:15 in my experiment. (2) The secondary exceptions are very rare as previous workers have pointed out, the frequency being only 0.53 per cent in my experiment. (3) The non-disjunction was verified on cytological ground also. There are 3 longer rod-shaped, 2 shorter rod-shaped and one dot-like pairs of chromosomes in the normal oogonial metaphase. The X-chro-mosomes are probably one of these two shorter pairs. No difference in length is found between X and Y. (4) Crossing-over in XXY females is not different from that in XX females. (5) XX to XXY ratio among regular daughters of XXY females has been found to be about 5:3, instead of 1:1. Such an abnormal ratio can be easily accounted for by assuming that one of the sex chromosomes (X or Y) lags on the spindle and does not enter the nucleus of either of the two newly formed cells at the first maturation division.
1. The number, size and shape of somatic chromosomes in three Disporum species and a variety of one of them were studied, and the comparison of chromosome types was made among them. 2. D. pullum, D. smilacinum, D. smilacinum var. ramosum and a form of D. sessile were determined to have 8 chromosomes in haploid or 16 in diploid. One other form of D. sessile showed 24 chromosomes in diploid. 3. The chromosomes were classified according to the length, relative position of constrictions in them and the presence or absence of satellites. 4. The determination of the length of chromosomes and the relative position of constrictions was made by a special method devised for measuring the true length of chromosomes with foreshortening. 5. On these bases 16 somatic chromosomes in each set of 3 species and a variety were classified into 8 types. 6. In order to compare the chromosome types among different species and variety, the percentage ratio of the whole length and that of the arms formed by the constrictions of each chromosome type were calculated to the sum of the whole length of all chromosomes in a set. 7. Between D. smilacinum and its variety ramosum, all chromosome types are much similar from the standpoint of their relative length and shape. 8. D. pullum, D. sessile and D. smilacinum and its variety ramosum show 5 types of chromosomes which are always similar in their relative length and shape, but if the comparisons are made between two different species of three, 2-3 types are more or less different. 9. The changes in the size and shape of chromosomes may have occurred during the phylogenetic courses of the species. This investigation was carried out in the Botanical Laboratory of the Utsunomiya Agricultural College, Utsunomiya, Japan. I wish to express my sincere thanks to Prof. F. KAGAWA for his helpful suggestion and guidance.
Der Sauerstoffverbrauch des Lungen- und Lebergewebes der Maus wurde nach der alten WARBURG'schen Methode gemessen. 1) Der Sauerstoffverbrauch des Lungengewebes war sowohl im Gasmedium als auch in der Ringerlösung von der Sauerstoffspannung abhängig, und zwar je höher die Spannung, desto größer war der Verbrauch. 2) Der Sauerstoffverbrauch des Lungengewebes war im Gasmedium größer als in der Ringerlösung. Der Verbrauch im Gasmedium während der ersten 20 Minuten war bedeutend größer. 3) Der Sauerstoffverbrauch des Lebergewebes war sowohl im Sauerstoffgasmedium als auch in der Sauerstoff-Ringerlösung fast gleich im Anfangsstadium des Versuches, aber er wurde in der Ringerlösung allmählich geringer. 4) Der Sauerstoffverbrauch des Lebergewebes war sowohl in 1 ccm als auch in 4 ccm Ringerlösung nicht wesentlich verschieden.