522 



Garden and Forest. 



[Number 462. 



leaven thus introduced ought at last to permeate the 

 whole mass of the people and bring about a clearer under- 

 standing of what forestry is, and what, when supported 

 by public interest and opinion, it may reasonably be 

 expected to do for the commonwealth. The fact that Penn- 

 sylvania has such an officer as Commissioner of Forestry, 

 and that the state publishes and disseminates every year 

 a careful report on the condition of its woodlands, is of 

 itself a distinct gain, for it means education. What the 

 commonwealth needs is enlightenment, and after this will 

 follow necessary laws and their enforcement. 



Fertile Crosses of Teosinthe and Maize. 



PROFESSOR A. DUCES sent in 1888 to the Cambridge 

 Botanical Garden, Cambridge, Massachusetts, several 

 Maize plants which he collected at Novo Leon, Mexico. 

 Seed was sown at the Garden, and the resulting plants were 

 studied by the late Dr. Sereno Watson.* Seed from the 

 second generation of the Cambridge plants was pro- 

 cured and planted in Philadelphia, developing into Corn, 

 which formed the basis for the botanical description of 

 Maize in Maize : A Botanical and Economic Study, ~\ pub- 

 lished in part second, volume first, Contributions from the 

 Botanical Laboratory of the University of Pennsylvania. 

 Later inquiries were made of Dr. Duges concerning his 

 discovery, and the following letter in French and dated 

 Guanajuato, September 22d, 1895, was received : 

 , The mai/e which Dr. Sereno Watson named Zea canina, 

 after the examples which I sent him, is known in Mexico as 

 " Maiz de Coyote" (Lupus latrans), "Teosinthe," " AseseV' 

 or "Cafe de Tabasco." We have considered it as Euchlagna 

 luxurians, Euchlaena Mexicana, or Reana luxurians. It ap- 

 pears that it has been cultivated in Europe and also in Mexico, 

 where it has been grown by Professor Jose C. Segura, Direc- 

 tor of the School of Agriculture at Mexico. This botanist dis- 

 covered at the end of three years of careful cultivation in good 

 soil that it changed to Zea mays, and that if abandoned to itself 

 under adverse conditions it reverted to Zea canina ; that is, 

 the same plant has a wild and a cultivated state. You are at 

 liberty to address on my part Professor Segura, who will be 

 pleased to give you the details. 



Some time elapsed after the receipt of the above letter, 

 when a letter was addressed to Professor Segura, of the 

 School of Agriculture, Mexico, who replied in Spanish, 

 under date of July 2d, 1896 : 



In reply to your letter, the manifest which I sent you with 

 the bags of seed explained that one bag contained seeds of 

 AsesS (Euchlaena Mexicana) ; another seeds obtained by hy- 

 bridizing Euchlaena Mexicana with common Maize. In con- 

 sequence, that which you term Zea canina, Watson, is not, 

 but the result of the hybridization of asese" with Maize. To 

 obtain this product, which is known in Guanajuato under the 

 name " Maiz de Coyote," and which you classify with maize, 

 sow three grains of the Asesg, and at a distance of 0.80 m. 

 three grains of Maize. As a result of the sowing in the month 

 of July, the Asese commences to shoot out its floral peduncle, 

 which should be cut off immediately after it appears [emas- 

 culation]. In August, when Indian Corn flowers, the Ases<5 is 

 fertilized! with pollen of Corn. % Harvest in October, and the 

 grains, upon examination, do not show any modification in 

 their form. The succeeding year sow the seed and a plant of 

 early habit will result, showing, in its small-sized ears, qualities 

 and appearances produced by the fusion of the ears of com- 

 mon Maize with the ears of the Ases£, grains of which I have 

 sent you. 



Kernels of both Teosinthe and Maize were sown in Phila- 

 delphia and the result of the planting watched with interest. 

 Before the plants had fully matured I went to Mexico and 

 visited Professor Segura at the National School of Agricul- 

 ture. Professor Segura became very much interested and 

 showed all the stages in the hybridization of Teosinthe 



,158. 



* Watson, Prcc. Amer. Acad. Arts an J Set., 



t Review. 1894, Garden and Forest, vii.. 28. 



■i It should be noticed here that the two plants are moncecious and protandrous ; 

 the order of flowering is as follows at Mexico : Male flowers of ases<?, then female 

 flowers of asese" and male of corn produced synchronously, then female flowers 

 of Maize, so that the ph vsiological arrangements in both plants in Mexico pre- 

 clude the use of pollen of asese in the fertilization ot Maize. 



with Corn, and very generously placed at my disposal a 

 series of specimens, permission at the same time being 

 given to publish the results of the experiments. 



Professor Segura has been carrying on his experiments 

 for the last five years. Maiz de Coyote was for a long 

 time known in Guanajuato as a very peculiar form, whose 

 origin was unknown. Professor Sereno Watson, to whom 

 specimens were sent, described them as a new species, Zea 

 canina, not recognizing them as of hybrid nature. 



The writer, who believed this form to be primitive, and 

 Professor Watson were both misled. Professor Segura 

 discovered ifs origin by accident, some very peculiar plants 

 having been found in a crop harvested from a field where 

 Corn and Teosinthe had been planted together. He wisely 

 experimented and conclusively demonstrated that Maiz de 

 Coyote was not specifically distinct, but of hybrid origin. 



Teosinthe, Euchlaena Mexicana, Schrad, is a plant of 

 several varieties native in Mexico, where the writer found 

 it growing wild in the Barranca Chica, near Guadalajara. 

 It is grown as a fodder-plant in most warm countries, sel- 

 dom flowering when planted in Europe. The two ranked 

 ears are clustered in the axils of the leaves, and have the 

 one fertile and one rudimentary flowers placed in a har- 

 dened cup-shaped depression of the rhachis. The male 

 spike, terminally borne, consists of two flowered spikelets, 

 with three stamens each in every flower. When Teosinthe 

 is crossed with Maize by the use of Maize pollen, the 

 hybrid progeny of the first generation shows a shortened 

 branch in the axil of a leaf with three or four ears clustered 

 together and surrounded by leaves which are commonly 

 called husks. These ears resemble very much those of 

 Teosinthe in that they are two ranked with the kernels in 

 the hardened- depression of an enlarged zigzag rhachis, 

 which shows the beginning of a cob-like axis, on which, in 

 this case, the grains are disposed in a distichous manner. 

 The kernels are larger, sharp-pointed and protrude between 

 the chaffy scales (glumes) from the cup-shaped depression 

 of the axis, which is, in this case, shallower than in Teo- 

 sinthe. The outer glume, which is hard in Teosinthe, 

 becomes larger and softer in the hybrid progeny. The 

 axis is still firm, glossy and chitinous. The second year, 

 Maize pollen is again used to cross with the hybrid plants 

 of the first generation. The result of this cross is a form 

 of ear in which the kernels are larger, fuller and more 

 rounded, while the corneous basin-shaped depression has 

 become smaller and more shallow. The kernels in this 

 generation are usually arranged in a distichous- manner. 

 The third year, pollen of Indian Corn is again used, and 

 the resulting ears are found to differ in the increase of the 

 number of rows of grains, four or more being present; the 

 pithy axis, or. cob, now becomes demarcated, and is 

 seen when the ear is broken transversely. The plants of 

 this year and of the fourth are evidently those described 

 by Professor Watson under the name Zea canina, and as 

 primitive ones by myself. 



A very fair, but reduced, illustration of the ears of the 

 fourth hybrid generation is to be found in the publication 

 referred to in the foot-note, plate xv., fig. 9, of the mono- 

 graph on Maize already referred to. The kernels of this 

 generation are somewhat top-shaped, three-eighths of an 

 inch long, white and sharp-pointed. The ears are usually 

 clustered together on a shortened branch, although in some 

 cases one ear may have taken the lead, having several 

 smaller ones at the base, as is to be found frequently in 

 ordinary Field Corn, when the husks are carefully removed. 



What, then, is the nature of Corn ? Several views may 

 be taken by the light suddenly thrown upon the origin of 

 the plant by these interesting cross-breeds or hybrids.* 



(1) That Maize is generically and specifically a distinct 

 plant. This is the view accepted by systematists and 

 the one current in botanies and floras generally. 



* Up to this point the results of the cross have been termed hybrids, because the 

 view was taken for clearness that two distinct species were used. We now desig- 

 nate according to the theory proposed the unions of two different varieties, as 

 cross-breeds, oi~ two different species, as hybrids. 



