58 



HARDWICKE'S SCIENCE-GOSSIP. 



petaloid or otherwise very different from their 

 original state. These persons, however, are not in 

 a majority, for in worlcs written years before the 

 " Origin of Species" disturbed the philosophic mind, 

 we find the orders of Marantacece, Zingiberacea: and 

 Orchidaccce as having stamens transformed into the 

 appearance of petals. Now it may be interesting to 

 consider how, when, or why, did such a change take 

 place. If the ancestors of such plants were anemo- 

 philous, as it is likely that they were, suppose an 

 individual to appear, with pollen grains coherent in 

 masses, it is obvious that they could not be trans- 

 ported by the wind so as to reach the stigmas of 

 other flowers. Now if such a phenomenon came to 

 pass before that winged insects were attracted by 

 flowers, as indeed it may have happened when no 

 winged insects existed, then such flowers must have 

 either been fertilised with their own pollen, or not 

 fertilised at all. Under such circumstances it is not 

 unlikely that the ancestors of orchids were subjected 

 to a long course of self-fertilisation, during which 

 most of the stamens became sterile and petaloid, and 

 even the stigmas could not escape the brand of 

 sterility that was stealing over the flowers when some 

 winged insects crossed their path to extinction and 

 saved them from it. If in the meantime any flowers 

 had appeared with all their organs barren and 

 petaloid, as in the double stocks of our time, the 

 plants bearing such flowers would perish, and their 

 race become extinct, leaving no record of their having 

 lived. So we do not find many double flowers in a 

 state of nature. But we do find plants whose flowers 

 are said to be habitually self-fertilised. What shall 

 we say of them ? In Darwin's book on the effects of 

 "Cross and Self- fertilisation," he has recorded 

 experiments which he made on plants for several 

 generations, extending over a period of eleven years, 

 a time long enough to afford valuable results, but 

 not decisive as to the ultimate consequences that 

 would follow in such a length of time as must have 

 elapsed since the species originated. We find, as 

 might have been expected, that the effects of self- 

 fertilisation are by no means uniform on the offspring. 

 Some of them seem to have been very diminutive, 

 and were thrown away by the experimenter. It is 

 by no means certain that such plants would be 

 thrown away by nature. Some of them would be 

 passed over by the sickle or the scythe that had cut 

 down taller plants, or might grow by the wayside and 

 the borders of fields where their very insignificance 

 might save them from destruction. So we find a 

 plant with prostrate stem, as JMalva rotundifolia, and 

 such other plants as V^icia hirsuta and Trifolium 

 procuinhcns, with flowers reduced and purposely 

 rendered inconspicuous, so that they are now but 

 little visited by insects. It is not among such plants 

 as these that double flowers occur. Their smallness 

 hinders them effectually from crowding out other 

 plants and filling the earth with vegetation. But 



among the plants on which Darwin made experiments, 

 three cases occurred of plants varying in such a 

 manner as to be more fertile with their own pollen 

 than they originally were, namely, with Mimulus. 

 Ipomoea, and Nicotiana. One plant of Ipomcea he 

 also mentions which he called Hero, from its exceed- 

 ing in height and size plants from seeds that were 

 cross-fertilised. 



Such plants as these were probably the ancestors 

 from which plants now under cultivation have been 

 for the most part derived ; Nature tolerating the 

 self-fertilisation of flowers on plants that are protected 

 by art from competition with others that are cross- 

 fertilised. Thus we can understand that cultivated 

 plants would be destroyed if neglected, by reason of 

 the delicacy of their constitution as compared with 

 others growing wild. But even among cultivated 

 plants Nature draws the line somewhere beyond which 

 self-fertilisation cannot go. Stamens become sterile 

 and assume the form of petals. Even during the 

 eleven years of Darwin's experiments he found some 

 flowers with stamens partially deformed and petaloid 

 on plants that were the offspring of self-fertilisation. 

 Sometimes the change comes on suddenly, but 

 perhaps more often gradually, under circumstances 

 not generally known. In an appendix to Dr. Masters' 

 "Vegetable Teratology," several facts are given 

 bearing on the subject. One is of a plant of Camellia 

 Japonica at Vienna, from which seeds were saved, 

 the flowers having been fertilised with their own 

 pollen. All the plants raised from these seeds bore 

 double flowers. This result was attributed by the 

 parties concerned to geographical and climatal 

 conditions, which might indeed have had something 

 to do with it, but it is at least as likely that the 

 progenitors of these plants had already gone through 

 a course of self-fertilisation which had reached the 

 limit Nature would permit. 



A double variety of Primula Sifiensis is also 

 mentioned as having been raised at Southampton by 

 seedsmen or florists, who say that to obtain double 

 varieties the raiser fertilise.^ certain fine and striking 

 single flowers with the pollen of other equally fine 

 single blooms, and the desired result is obtained. It 

 is admitted, however, that there is a reservation of 

 some important item which is kept as a professional 

 secret. Now Darwin tells us that flowers fertilised 

 by the pollen of other flowers on the same plants 

 yield seeds which give origin to plants having no 

 advantage over those raised from the seeds of self- 

 fertilised flowers ; so that it is quite possible that the 

 whole secret may be revealed by adding four short 

 words, thus, after the words single blooms read " on 

 the same plant." This I write hypothetically, as an 

 inference deduced from the premises hereinbefore 

 stated, for nobody has told me anything on the 

 subject. When I once asked a seedsman by what 

 means double varieties of the Japan pink were 

 obtained, he told me by hybridising with another 



