130 THE BOTANICAL MAGAZINE. [VoL xxxV. No. 4i«. 







lyiS. Notes on Algae New to Japan. Concluding Reruaik. (Ibid., XXXII, p. 175-187), 

 1919 The Germination and Development of Some Marine Algae. I. (Ibid., XXXIII, 



p. 73-92, pi. I & 2 textfigs.). 

 1919. The Germination and Dtvelopment of Some Marine Algae. II. (Ibid., XXXIII, 



p. 171-184, pi. II). 



1919. A Monograph of the Genua Alarin. (Journ. Coll. Sc. Imp. Univ. Tokyo, 



XLIII, Art. 1, p. 1-145, pi. I-XIX). 



1920. Novae Algae Japoniae. Decas I-III. (Bot. Mag. Tokyo, XXXIV, p. 1-12). 



Resume of the Article in JapaneEe. 



MiTflUHARU IsHiKAwA : — Oil the ChroDiosonies of Lactuca. 



The author has invesiigated the meiotic chromosomes iu the 

 pollen mother cells in the folio wmg 15 species and 5 varieties of 

 Lactuca, many of which grow wild in Japan. 



L. laciniata. (9) L. I. var. plalyphylla (5) L. Maisumurae (8) 



L. Haddeana (9) L. dsnticuluia (5) L. famagauensis (8) 



L. iriangulaia (9) L. d. var. pinnat! partita (5) L. chinensis (16) 



L. scariola var. saliva (9) L chelidonifolia (5) L. deniata var. genuina (12) 



L. villosa (9) L. debilis (24) L. d. var. dbiflora (12) 



L. Keiske^na (5) L. slolonifera (8) L. d. var. alpicola (7) 



L. lanceolata (5) L. repens (8) Chromosome numbers are 



given in parentheces. 



He has classified these species by the form, size and number of 

 the chromosomes and has obtained the five groups, which also differ 

 from one another in the general taxonomic characters. The figures 

 with brief accounts are given in a tabulated form. Further extended 

 work is under way. 



In the October number of this magazine of 1920, Dr. Nakai has 

 published that the Japanese species of Lactuca should be divided into 

 the four genera, i.e. Lactuca, Crcpidiastrum, Paraixeris and Ixeris. 



It is interesting that his results agree with those of the anthers ; 

 his genus Lactuca corresponds to the first group of the auther, 

 Crepidiastrum to the second, Paraixeris to the third,- and Ixeris to 

 the fourth and fifth. 



It is noteworthy that the results obtained by the taxonomic 

 and cytological studies independently done, are in accordance with 

 each other though there are a few points which do not agree in 

 some respects. 



