450 



The Journal of Heredity 



considered ver>' suitable for my pur- 

 poses, and from which I hojjed for 

 economic results of importance. These 

 were the Karly Harvest l)lackl)erry and 

 the Austin dewberry-. 



The Marly Harvest, assijjned b\' 

 systemalists to Rubus ftoridiis, has 

 erect, fluted canes with few spines, 

 tri-pinnate leaves, compact and elon- 

 gated flower clusters with short bracteo- 

 late pedicels, and small flowers. The 

 fruit also is small, but one of the 

 sweetest, and the seed the smallest of 

 any of the culti\ated blackberries. 



The Mayes dewberry, also called the 

 Mayes Hybrid Austin and Austin- 

 Mayes, referred to R. haileyanns x 

 floridus, has a prostrate, diffusely 

 branching growth with terete canes 

 co\ered with a few rather small, 

 straight spines. The lea\es are 3 to 5 

 foliate; the flowers large, on elongated 

 pedicels in loose, flattojiped, braclless 

 clusters. The fruit is large, composed 

 of a few but large drupelets with very 

 large seeds; the flavor is quite sour, and 

 the aroma not perceptible. 



From a cross between these two 

 forms, Mayes being the mother, I 

 grew to fruiting an 1' i generation of 28 

 plants. The characters of Mayes were 

 so strongly dominant in all of them, 

 as almost to exclude all traces of the 

 other parent. All of these plants 

 flowered profusely, and some produced 

 many fruits which, however, were more 

 or less imperfect and irregular in form, 

 due to two kinds of drui)elets, small 

 and large intermixed, this l)eing the 

 most exident character of their hybrid 

 origin. 



An indi\idual, in which the charac- 

 ters from both parents were more 

 eivdent than in the rest, was screened 

 off from foreign pollination. F"rom 

 the seed of this, an Fj generation of 

 425 plants was raised. Of these, 367 

 had the characteristics of Mayes, 37 

 might be classed as intermediate, and in 

 21 the characters of Farly Harvest 

 were predominant. Two of the most 

 typical of the last named group were 

 screened. They flowered profusely but 

 set no fruit. All other plants of that 

 same generation, exposed to foreign 



pollen, were more or less sterile, or set 

 imperfect and inferior fruit. 



From the reciprocal cross, with 

 Farly Harvest a& the mother and 

 Mayes as the pollen parent, I failed 

 to obtain any progen>-; nor did I suc- 

 ceed any better with it as mother, 

 using pollen from other s(jurces. — The 

 flowers of Farly Harvest are strictly 

 self-fertile and, generally, self-fertilized. 

 — What bearing that fact may have on 

 the difficulty of effecting a cross, I do 

 not know. 



For some years. I made numerous 

 attempts to oinain crosses between 

 \arious forms of our culti\ated black- 

 berries and dewberries, and failures 

 resulted either from perfect or partial 

 sterility; or the hybrids disgusted me, 

 because of their confused characters 

 as well as their utter failure to give 

 any promise of impnnement for eco- 

 nomic purposes. In fact, they all 

 bore the stamp of degenerates in that 

 respect. 1 will only mention one of 

 these cases, namely, a cross between 

 the Mammoth blackberry and the 

 Dallas blackberry. 



THE MAMMOTH X DALLAS CROSS 



The first generation of this cross 

 consisted of 11 plants, with the vege- 

 tative organs uniformly intermediate 

 between the parents. In the flowers, 

 the following anomalies were notice- 

 able: the stamens were much reduced 

 in nimiber and their filaments in 

 length; the disk, upon which the 

 stamens were inserted, had de\eloped 

 into a ring of pai)il!a-like swellings 

 bearing fascicles of pistils replacing a 

 goodly number of the stamens. Such 

 stamens as developetl were, however, 

 fertile to a considerable degree, since 

 under screen fairly well dexeloped 

 fruits were obtained. In the second 

 generation, this anomaly in the flowers 

 increased, esj)ecially in those where 

 the Mammoth characters were domi- 

 nani. In m)mu'. the stamens had 

 \anislu(i altogether, and the accessory 

 pistils had become perfect and fertile, 

 dcNeloping drupelets of normal ap- 

 pearance when polk-ni/.i'd with pollen 

 from tlu' Log. HI bl.ickbcrry (logan- 

 berry). 



