August 25, 1893.] 



SCIENCE. 



105 



that the foot rested upon the sole. He had also shown 

 that while the primitive types possessed cone-shaped 

 teeth, the more differentiated they became the more com- 

 plex the teeth were. An interesting statemeiit in regard 

 to the dental formulas of various orders was given. With- 

 out going into details, it may be said that the speaker 

 argued for the three great groups of mammals, — mono- 

 tremes, marsupials and placentals, — a common origin far 

 back of Jurassic times, for the three were then plainly 

 differentiated. These classes arose from a promammalian 

 type, which was, in its turn, an offshoot from a still sim- 

 pler form, a second offshoot from which developed into 

 the reptilian type of life. The horse he considered as 

 originating on the North American continent, and he 

 pointed out the interesting fact that the disappearance of 

 many of the huge forms of mammals that once peopled 

 our western plains seemed co-incident with the introduc- 

 tion of grasses. 



Professor Bessey, before Section G (Botany), gave an 

 excellent address upon classification. He pointed out the 

 anomalous fact that while botanists have long recognized 

 that the present scheme of classification was defective, 

 they still adhered to it. Theoretically discarding it, prac- 

 tically they used it. He showed that there may be 

 degradation as well as advancement in evolution, and 

 that what seemed the lowest forms of dicotyledons, from 

 their floral structure, were not necessarily primitive types. 

 He therefore interpolated the apetalous orders of the 

 ordinary classifications among the polypetalte, as de- 

 graded types of jjolyp^talous flowers. He outlined 

 what seemed . to him to be a natural classification, 

 considering the Ranuueulaceae as the most primitive 

 flowers. The greatest deviation, therefore, from this 

 type was the highest in organization. He believed that 

 with but little modification the sequence of orders in our 

 modern text books could be used to express the natural 

 relationships of plants. Of course such a scheme as a 

 lineal arrangement was out of the question. He, in com- 

 mon with many others, recognized the Compositse as the 

 most highly organized of the dicotyledons, and the Orchi- 

 dese were placed at the head of the monocotyledons. 



In the general session of Thursday evening the retiring- 

 president. Professor LeConte, of California, delivered an 

 address upon the "Origin of Mountains." In opening, he 

 defined a mountain as the result of a single earth effort, 

 occufiying a short or a very long time, while a mountain 

 range was the result of a succession of earth throes. The 

 thickness of the strata of mountains varies, but it is al- 

 ways great. In the Appalachians the Paleozoic is 40,000 

 feet thick. The Mesozoic of the Al]ps is 50,000 feet, and 

 the Cretaceous of California is 20,000 feet. The sediments 

 of the Appalachians thin out to the west to only one or 

 two thousand feet, so that mountains may be considered 

 as lines of exceptionally thick sediments. They are, at 

 the same time, lines of exceptionally coarse sediments. 

 Foldings and faults are also characteristic of these 

 features of the earth, the folds being single or many, and 

 the faults being sometimes of enormous extent. Faults 

 of 20,000 feet occur in our western region. After this 

 general discussion of features, the causes were considered. 

 There are both formal and physical explanations. The 

 first explain the cause from the geologists' point of view, 

 and the second from that of the physicist. The first may 

 explain one or more of the phenomena, but the last must 

 explain all of them. Various illustrations were given of 

 these, and then the formal explanation of facts was taken 

 up. Mountains are born of sea-margin deposits, the 

 loaded sea bottoms inducing sinking of the denuded land 

 surface, and the mountains are formed by lateral crushing 

 and upthrust. He did not beheve in the theory of a 

 liquid interior, with a solid crust, stating that a globe as 



solid as glass or steel would assume the oblate spheroid 

 form, as the result of rotation. He argued at length in 

 favor of the lateral thrust origin of mountains, and ex- 

 amined objections urged against it. He also outlined 

 other theories of mountain origin, and pointed out their 

 defects, declaring, however, his entire willingness to give 

 up his theory whenever any better one had been pre- 

 sented. 



THE COENELL MIXTUEE. 



BY M. V. SLINGERLAND, CORNELL EXPERIMENT STATION, ITHACA, N. Y. 



Last winter, while experimenting in the making of the 

 different insecticides and fungicides, I succeeded in form- 

 ing a combination which, at the time, seemed to be an 

 almost perfect panacea for all the insect and fungoid ilia 

 that might affect the fruit grower. When it was shown 

 to Professor Bailey he immediately dubbed it "The Cor- 

 nell Compound or Mixture." 



In making the mixture I combined the following well- 

 known insecticides and fungicides: Paris green, kerosene 

 emulsion and Bordeaux mixture. Simple enough, was it 

 not ? And what a field of jDossibilities and probabilities 

 it seemed to cover when the theory of the combination is 

 rightly understood. In the Paris green (which I prefer 

 to London purple, on account of its containing less solu- 

 ble arsenic, and is thus less liable to injure tender foliage, 

 and still better, the copper of the Paris green gives it 

 noticeable fungicidal properties) we have the best, chea23- 

 est and most i^racticable insecticide for all biting or chew- 

 ing insects like the codlin moth, the potato beetle, and all 

 the leaf-eating caterpillars and beetles. The kerosene 

 emulsion is also well known as the best, cheapest and 

 most practicable insecticide for general use against all 

 insects which obtain their food by sucking it through 

 slender beaks with which they pierce the tissues of the 

 plant. Familiar examples of this group of insects are the 

 pear psylla, the plant-lice and the squash bug. And 

 finally, the Bordeau mixture, which now ranks first among 

 the fungicides in effectiveness against the worst fungoid 

 diseases, like the apple scab, the jpotato blight and rot, 

 and the plum and peach fruit rot. One can thus under- 

 stand what a destructive power there seemed to lurk be- 

 hind the mask of the Cornell mixture. 



Many experimenters have shown that when the Bor- 

 deaux and Paris green are combined, the destructive 

 effect of neither is lessened, and we know that the lime of 

 the Bordeaux mixture converts all of the soluble arsenic 

 of the Paris green into an insoluble compound, thus al- 

 lowing the use of the arsenite at nearly twice the strength 

 usually used without danger to tender foliage. The two 

 are easily combined and are to be recommended for gen- 

 eral use. 



Attempts have been made to combine the insecticides 

 Paris green for biting insects, and kerosene emulsion for 

 sucking insects, but without success; the arsenite cannot 

 be made to unite satisfactorily with the oily lighter emul- 

 sion. I have seen no accounts of any trials to combine 

 the Bordeaux mixture with kerosene emulsion. Such a 

 combination strongly recommends itself to piear growers 

 especially, who have the pear psj'lla to fight, and who 

 wish to exterminate the scab at the same time. My ex- 

 periments in this line were suggested by a large j)ear 

 grower who had these foes to meet. 



My Bordeaux and emulsion were made according to the 

 directions which are appended below.* When the dii-ec- 

 tions were carefullj' followed I found that I could quite 

 readily combine the two in any proportions required, and 

 the resulting mixture remained stable for weeks; and in 

 fact the Bordeaux, as a mechanical mixture, was imj)roTed, 

 for the emulsion held the lime in suspension, so that its 

 tendency to settle to the bottom, and thus requii'e con- 



