202 



The Journal of Heredity 



cars would apjjear alike and discrimina- 

 tion would be impossible. 



One all-colored ear havinj^ practically 

 all of the seeds infested is shown in 

 Table 1. The percentage of double- 

 infested seeds on this ear is 23.6 ±2.1% 

 while the percentage of infested seeds 

 on the mottled ear is 33. 2± 1.8';'(. If 

 this difference is considered significant, 

 it will ha necessary to look ujjon the 

 ])rotection afforded by the mottled 

 color as not quite so effective in pre- 

 venting initial injury as actual infesta- 

 tion is in preventing double infestation. 

 In other words the mimicry is not quite 

 perfect. 



It would be interesting to compare 

 the degree of infestation of mottled 

 seeds with seeds entirely white, but no 

 white ears of the mottled type were 

 present in the collection, and an examin- 

 ation of several importations received 

 directly from Bolivia in previous years 

 revealed no all-white ears of this type. 



The moth Sitotroga cerealella first 

 attracted attention in Europe in 17 28 

 and is supposed to have reached this 

 country about thirty years later. Of 

 its occurrence in Bolivia nothing seems 

 to be known. The fact that the ancient 

 Incas were accustomed to store large 

 quantities of corn might seem to indicate 

 that the insect was not present. It 

 would appear, therefore, that although 

 mottled seeds may be in some measure 

 ]jrotected, it would be quite unwar- 

 ranted to ascribe the development of 

 the mottling to selection. It must be 

 remembered that the degree of protec- 

 tion which the mottling of the seeds 

 seems to afford may after all be but 

 the result of accident. The resemblance 

 is so close, however, that the j^ossibility 

 of its affording ])rotection seems worth 

 considering. A true test will await an 

 ear having both self-colored and mot- 

 tled seeds, a combination which is 

 genetically possible. 



Experience with Loganberry Hybrids 



W. O. Backhouse's remarks on logan- 

 berry seedlings (Journal of Heredity, 

 November, 1916), mentioned experi- 

 ments made by Laxton Bros, in England. 

 Notice in the Gardeners' Chronicle (Lon- 

 don), evoked a communication (Decem- 

 ber 23) from Laxton Bros., in which, 

 after stating that they are "substan- 

 tially in agreement" with Backhouse, 

 they say: 



"In the la.st ]:)aragraph you make 

 reference to the Phen(jmenall)erry as 

 being of undoubtedly hybrid origin. 

 We are firmly of opinion that this is 

 nothing more nor less than a seedling 

 from the Loganberrv, which it very 

 closely resembles, although slightly larger 

 and sweeter — in fact, the difference is so 

 small to the eye that we do not think 

 we could jiick out the i:)lants from the 

 Loganl)err\' unless they were in the 

 fruiting stage. You also figure the 

 Lowberrj'- as being a hybrid between 

 the Loganberry and the Blackberry. 

 We do not think this is a fact. We 

 ourselves have imported a variety un- 

 der the name of Californian Mammoth 



Blackljcrry, from .\merica, which we are 

 unal)le to distinguish from the Lowberry. 

 We draw your attention to these 

 matters, as when \-our ]mper makes 

 authoritative statements they are apt 

 to be quoted in years to come. There 

 are undoubtedly two Rubus hybrids in 

 commerce, namely, the Mahdi (be- 

 tween a yellow Raspberry and the 

 Loganberry) and the Laxtonberr\-. We 

 have obtained F2 seedlings from the 

 Mahdi — amongst them a Rubus similar 

 to a yellow raspberry — and the Laxton- 

 berry is a cross between vSuperlative 

 Raspberry and the Loganberry. Both 

 these hybrids are more or less self- 

 sterile, and require planting amongst 

 other Rubi. We have purchased from 

 Messrs. Veitch the stock of the Veitch- 

 berry, which is a h\-bri(l between the 

 Blackberry and the IvOganbeiry. This 

 is not at present in commerce. There 

 have been many seedlings from crosses 

 1 jet ween the Loganberry and other 

 Rubi, but in nearly all cases self- 

 sterility has prevented them being of 

 anv commercial value." 



