1919. PethybrIDGE. — Heterocarpy in Picris echioides. 31 



fruits germinated within seventeen days, the remaining 

 fruits in each case were dead and mouldy. The two kinds 

 of fruits, therefore, germinated equally well. Moreover, 

 there was no difference in the promptness with which the 

 viable fruits of the tw^o kinds started to sprout, so that 

 the " germinating energy " was also the same. 



It wdll naturally be asked whether the two different 

 kinds of fruits produce plants which are morphologically 

 identical. This question cannot be answered with absolute 

 certainty at the moment, but as far as can be seen up to 

 the present seedlings raised from the two kinds of fruit 

 and growing in pots side by side are indistinguishable. 

 Moreover, the plant raised in 1914 from a ray fruit was 

 identified at once as Picris echioides and no peculiarity in 

 structure was observed. Further information will be 

 available when the seedlings, at present being grown, flower 

 and fruit which will probably be during the coming summer. 

 There seems no reason to expect any variation for, after 

 all, it is the fruits which are different ; the seeds and the 

 embryos within them appear to be quite similar. 



At the time when the observations recorded here were 

 being made I was not certain whether heterocarpy in 

 Picris echioides had been recorded by any previous writer, 

 or not. My first search in the literature failed to find any 

 such record, but a further hunt, aided by my friend, 

 Mr. A. D. Cotton, of Kew, resulted in the discovery of 

 Delpino's account of the matter, published in 1894. This 

 author briefly describes the external appearances of the two 

 kinds of fruit but makes no reference to the relative number 

 of each of them present in each head. With regard to 

 the supposed functions of the two kinds of fruit, I am 

 not, however, in entire agreement with him. He lays 

 stress on the poorer development of the pappus in the 

 ray fruits, and even goes so far as to say that it is a useless 

 organ perpetuated by heredit}/, although it cannot exercise 

 its function. Hence, he considers that the ray fruits 

 serve merely for dispersal " in loco," if such a contradiction 

 of terms may be pardoned. I do not regard the pappus 

 of the ray fruits as a useless organ, at all. On the contrary, 

 I think it is probably of just as much service to the ray 



