Volume IV 



JANUARY, 1915 



No. .s 



A GENETIC AND CYTOLOGICAL STUDY OF 

 CERTAIN TYPES OF ALBINISM IN MAIZE. 



New v,,,.,.^ 

 «otan/c .1 



By frank C. miles, 



United States Department of Agncultun', Washinffton. D.C. 



»/ 



Preinoxts Investigations. 



It has loMi;- hoiMi noted thai while seedlings, •.\m\ variegiited unes ns 

 well, occasionally occur among many of our connnmi plants, hui only in 

 recent years has any systematic study of the problem been made. 



Baur(l, -1) in UK)7 (later, in IDOS) reported liis study of the ytdlow- 

 leaved type of Antirrhinnni and Pelargoniinn. The yellow plants are 

 not capable of assimil.'itino' carbon dioxidi', .nnd eonscHpiently they can- 

 not live. This type of plant can exist only as a hybrid with a yreen 

 race, 'riie hybrid is an inli'nsi\(' yellow or " .\iire,-i-K;irbe," .and in the 

 second generation one-fourth of the plants are pure green which breed 

 true in succeeding generations, two-fourths are of the "Aurea" type 

 which segregate again in the next generation, and one-fourth are pure 

 yellow plants which theoretically should breed true, a test, however, 

 being impossible because the yellow plants always die in I lie seedling 

 stage. 



In 1909 Correns(6) reported examples of what, has beei\ called the 

 "chlorina" type of plants in Mirahiiis jtthtpa. and in i'rtiea piliilijrra. 

 Haur(.'}) later repoi'ted the same type in Antirrliiiniiii. In these eases 

 the colour stutV (including the xant.hophyll and eai-ot-in ,-is well as the 

 chlorophyllin) seiMns tn be reduced in intensity, .•uid also ap|)e,Mrs to be 

 dinunished in quantity. In inheritance this "chlorina" character 

 behaved as a simple Mendelian recessive. 



In llie same pa|)er ((i) Correns also reporteel a peculiar manner of 

 inheritance of leaf colour in Alirabilis Jala pa. He states that, the 

 leaves of the plants are irregularly spotted with yellowish white, a 



.Tciuiii. of (li'u. IV 18 



