340 MESSRS. C. SHEARER, W. DE MORGAN, AND H. M. FUCHS 



The following are cases of offspring following the maternal parent from other causes 

 than those of heredity. 



CoRRENs(15) made crosses between Mirahilis jalapa (which has normal green 

 leaves) and Mirahilis jalapa albomaculata (with irregularly yellowish white and 

 green spotted leaves). The leaf character of the hybrids is always that of the 

 maternal parent. This is probably not due to inheritance, but to the transmission of 

 a disease through the maternal cytoplasm. Two cases in which one parent has a 

 preponderant influence on the nature of the hybrids ai-e given by Bateson (5). The 

 first was worked out by Biffin and concerns crosses among wheat plants. When 

 a variety having long glumes and seeds was crossed with a variety having short 

 glumes and seeds, the seed character of the offspring in the F, generation resembled 

 that of the maternal parent. The latter exercised a control over the size of the 

 seeds, but this was probably due to the size of the maternal envelope, and was 

 not a true case of heredity. The second case concerns the seed-coats of peas, and 

 was worked out by Tschermak. The only part of the work which concerns us 

 here is the following. When a plant having round seeds is crossed with anotlier 

 having " indent " seeds, the seed character of the hybrids is that of the female parent. 

 Bateson pointed out that the cause of this is probably similar to that in the case of 

 the wheat seeds. 



While the case of (JEnothera is comparable with the inheritance through one parent 

 in Echinoderms, the direct influence of the mother on the form of the seeds is a 

 phenomenon of another nature. Referring to the latter cases Bateson (5) says : 

 " This group of cases introduces us to several points of interest. We have first the 

 remarkable fact that the mother plant can impress varietal characters on her offspring 

 by influences which are not heredity in the ordinary sense. Seeds are in botany what 

 larvae are in zoology, and no example is yet known in which the maternal impress 

 extends beyond the seed stage. But without any serious stretch of the imagination 

 we may suppose that a maternal impress may be such as to produce a lasting effect, 

 at least for the life-time of the immediate offspring." We would rather say, however, 

 that seeds in botany may perhaps be compared with embryos in zoology, but not 

 with larvae. It is well known that embiyos can have their characters aftected when 

 they undergo a part of their development in contact with the mother. It is, however, 

 impossible that such characters as those we have investigated in the free-living larvae 

 of Echinoderms could owe their development or non-development to any parental 

 influence other than true heredity. 



It may be urged that this inheritance through the female parent alone, in crosses 

 between the Echinus species, is not a true case of hybridization at all,* but is 

 pseudogamy. That is to say, the male element took no part in the formation of 



* Although the reciprocals of our crosses could in 1909-11 be said to be " purely " maternal with regard 

 to the characters considered in the late larvae, yet the larvse themselves were not " purely " maternal, for 

 they always were influenced in general shape by the male parent. 



