126 



Garden and Forest. 



[Number 264. 



recently given in the Gardeners' Magazine by a well-known 

 correspondent. The writer says that 'early in 1892 he saw a 

 fine specimen of the Persian Cyclamen in full bloom that had 

 been g-rown in a cottage-window for the past nineteen years. 

 It had at that time nearly one hundred and sixty flowers upon 

 it, and was in robust condition. This particular corm was two 

 years old when it came into the hands of the present owner, so 

 that it must be now nearly twenty-two years old. The blos- 

 soms are delightfully fragrant, and they seed freely, as some 

 of the progeny is in cultivation at the present time. 

 CambridRe. Mass. M. Barker. 



spring Cultivation of Chrysanthemums. 



CHRYSANTHEMUMS intended for specimen plants or cut 

 flowers during the coming season need cultural attention 

 now and will continue to require it. From new varieties, de- 

 livered by the dealers in March, it is possible, with proper 

 management, to secure two or three good plants for exhibi- 

 tion flowers and still have the stock plant left in good form. 

 For this purpose only the soft tips are taken, thus ensuring 

 the break immediately below. If specimen flowers only are 

 wanted the tips may be cut into the hard wood, when, instead 

 of breaking along the stem, suckers will be developed from 

 the base, and these make the very best cuttings. After this 

 treatment the original plant is of little use for making a 

 specimen. 



The standard varieties on hand may be established in five 

 or six inch pots. If not already done, this should be attended 

 to at once. A moderately rich compost should be used at this 

 stage, pressed firmly if the soil is light and loosely if it is 

 heavy. It is very important at all stages that the drainage be 

 free. 



The plants should be placed in cold frames as soon as this 

 is safe, to encourage a good stocky growth, and the final shift 

 be made into ten or twelve inch pots about the 20th of May in 

 this latitude. My plan has been to turn the plants then into 

 the frame for a week or longer, that they may have the pro- 

 tection of sashes in case of heavy rain before new roots are 

 made. 



Stopping is an important operafion to secure good symmet- 

 rical plants. The plants should be examined for this purpose 

 every few days throughout the season. Untrained plants be- 

 come leggy, and stopping is also an important factor in retain- 

 ing the lower foliage, without which no specimen is perfect. 



Wellesley, Mass. T. D. H. 



Correspondence. 

 Hybrid Genera. 

 To the Editor of Garden and Forest : 



Sir, — I see in your number for January i8th that my friend, 

 Mr. Watson, following the precedent of no less an authority 

 than Dean Herbert, raises objections to so-called bigeneric 

 hybrids. Ry implication, at least, he casts some amount of 

 disapprobation on me for having conferred a name or names, 

 the construction of which must, if he isrightin his contention, 

 be altogether faulty and misleading. 



I believe in certain quarters I am credited with having been 

 the first to apply a hybrid name to the product of two assumed 

 genera. It may be so, but I have a vague impression, which 

 I have not yet been able to confirm, that I was not the first 

 person to follow such a course, and that there were bigeneric 

 liybrids — named as such — previous to my Philageria x. Be 

 this as it may, I do not wish to shirk my responsibility. If 

 similar circumstances were to arise to-morrow I think I should 

 follow the same course. The reason will be obvious when I 

 have concluded. 



Mr. Watson, I am sure, would disclaim the ability to define 

 accurately what is a genus, or what is a species. I should be 

 equally unwilling to advance any claim to infallibility. Both 

 he and I, for our respective purposes, are obliged to adopt 

 certain more or less arbitrary postulates and to say this is a 

 species, or that is a genus. What we include within these 

 limits is partly an affair of judgment and experience, pardy of 

 expediency. Moreover, we take genera and species as 

 we find them described by our predecessors. It is obviously 

 impossible for us to study every genus as a monographer 

 does. The number of species and genera upon which any 

 botanist is entitled, from personal research, to pronounce an 

 authoritative opinion is infinitesimal in proporfion to the total 

 number. He is compelled to rely upon the opinion of others. 



The same arguments that Mr. Watson uses in the case of 

 genera were once employed in the case of species. Such a 

 thing as a hybrid between two distinct species, it was averred, 



could not exist. The fact of the existence of a so-called hybrid 

 was taken as evidence that the two parents belonged to one 

 and the same, not to two different species. If any one still 

 prefers to adopt that view, it is not for me to say nay. To en- 

 ter into any discussion on the matter would occupy much 

 more space than the Editor of Garden and Forest would, if 

 I may judge from my own experience, be able to afford. I 

 would simply record my opinion that, at least for garden pur- 

 poses, it is expedient to admit the existence of species and of 

 hybrids between them. As a matter of physiology, when I 

 read of the characteristics of natural hybrids being produced 

 artificially, as in many Orchids, and of the counterparts of arti- 

 ficial, hybrids being found in a wild state, I think we have 

 stronger grounds than mere expediency to justify our proced- 

 ure. But this part of the subject I do not wish just now to enter 

 upon ; I simply repeat that in gardens we cannot do otherwise 

 than recognize certain forms as hybrids, and this being so it is 

 expedient to give them names indicative of their origin. If 

 this be admitted in the case of species, a fortiori it must be 

 admitted in the case of genera. The plant known as Phila- 

 geria X is not a Philesia, it is not a Lapageria. What is it ? In 

 the case of Urceocharis x the gap is wider stiU. No gardener 

 would confound UrceolinaandEucharis, and Messrs. Clibrans' 

 plant was neither the one nor the other. 



The recent publication of Dr. MacFarlane's paper on the 

 microscopical structure of various hybrids shows that in ana- 

 tomical construction, as well as in outward appearance, the hy- 

 brids are intermediate between their parents. It shows also that 

 the variation in minute structure is greater than we usually 

 see in different species of the same genus. Considering all 

 these circumstances, I remain of opinion that it is desirable, 

 for practical purposes, to give these hybrid producfions appro- 

 priate names according to their degree of distinctness. 



As to the bearing these intermediate forms have on the 

 question of the origin of species and of genera, that is, 

 as I have said, too speculative a matter to be entered upon 

 here. I would merely say that I am, so far as I see, more 

 nearly in accord with Mr. Watson in his speculative than in 

 his practical views. „ _ ,, 



London. Maxwell T. Masters. 



Relation of Yield of Potatoes to Weight of Tuber 



Planted. 

 To the Editor of Garden and Forest : 



Sir, — For many years there has been much written and said 

 concerning the amount of seed tuber to be planted per hill to 

 secure the best and most productive crop of potatoes. The 

 ordinary custom adopted in many tests was to plant in sep- 

 arate plats seed potatoes of different sizes, or to cut tubers in 

 various ways, and plant given areas with certain forms of cut- 

 tings. The weight of the seed was guessed at instead of definitely 

 ascertained. To get more definite information on the weight 

 of the seed planted and the resulting crop, in 1889, at the Ten- 

 nessee University Experiment Station, I carried on quite an 

 extended experiment ; the individual tubers planted were first 

 weighed and a record kept of the growth and harvest of each 

 hill. Prime New York State Early Rose tubers were used and 

 the potatoes were planted whole, and in eight lots, grading 

 from tubers weighing from one to two ounces to from twelve to 

 fourteen ounces. 



The following table is of special intei-est and importance as 

 bearing on the results : 



Weight tubers Averagfe height Total average Yield per hill, 



planted. plants grew. weight. Number. 



12 to 14 ounces. 20 inches. 29.8 ounces. 19.3 



10 to 12 " 20 " 20.9 " 19. 1 



8 to 10 " 17 " 26.5 " 16.7 



6 to 8 " 17 " 22.8 " 16.3 



4 to 6 " ifyyi " 21.4 " 15.4 



3 to 4 " isK " 19-8 " 148 



2 to 3 " 16X " 19-1 " ii-S 



I to 2 " 15 " 17.4 " 9.5 



Other experiments were also conducted, in which it was 

 shown that the larger the seed-piece planted the greater the 

 yield. But it was also demonstrated that the large and whole 

 tubers produced smaller and poorer merchantable potatoes 

 than did halves, quarters or single eyes. 



For several years past Dr. J. C. Arthur has been investiga- 

 ting this same problem at the Purdue University Experiment 

 Station, from the standpoint of the physiological structure of the 

 tuber. A very large amount of experimental work has been 

 done, in the field, with weighed seed-pieces or tubers. This 

 involved a study of the entire structure of the tuber, and the 

 relation of the number of eyes to the tuber; the number of 

 stalks compared with number of eyes ; number of stalks com- 



