August 12, 1892. J 



SCIENCE. 



93 



To this destruction he attributed the absence of the second brood 

 which published accounts led him to expect. I recorded these 

 facts in my Report for 1889, claiming positively that there was a 

 single brood only at New Brunswick. My observations, carefully 

 repeated in 1890 and 1891, simply confirmed this conclusion. 



These observations were presented at a meeting of the Entomo- 

 logical Club of the A. A. A. S., and, though he could not gainsay 

 my facts, Dr. Riley yet doubted the correctness of my conclusion, 

 as his pai er in Science also shows. I therefore resolved to repeat 

 my work yet more carefully in 1893 and to make it conclusive if 



possible. The first signs of the beetles were noticed on May 17, in 

 the form of small round holes eaten in a few leaves; on the 19th 

 a few of the beetles were seen, and after that date they increased 

 rapidly in numbers for some time. The weather for a few days 

 was cold and wet, the insects were sluggish, and no eggs were 

 observed until May 39. For special observation I selected a small 

 tree between my home and the laboratory, which I passed several 

 times daily, could see all parts of easily, and which was a prime 

 favorite with the insects. 



Eggs began hatching June 6, while yet, oviposition continued. 

 After the middle of the month the hibernating beetles diminished 

 in number, and on the 3(Jth not a beetle could be found. June 

 39 the first pupae were formed and larvae matured daily thereafter 



in greater abundance. At this date a very few unhatched egg- 

 clusters were yet to be found, but of those collected, only one 

 mass gave larvae July 1. Since that date and up to date of writ- 

 ing (Aug. 1), there has not been a cluster of eggs on any tree that 

 I have examined, and I have closely scanned many dozens, large 

 and small. Early in July I gathered in over 300 pupse and mature 

 larvae under the observed tree, and placed them in breeding-cages 

 and jars Adults began to appear July S, and very rapidly there- 

 after in the open air as well as in my cages. It is interesting to 

 note that on June 39, when I secured the first pupa. Dr. Riley 



already had eggs of a second brood. The beetles bred by me fed 

 readily and abundantly for nearly three weeks, and then more 

 slowly, until at this time they refuse to feed entirely. During all 

 this time there has not been a copulation nor an egg-mass in any 

 jar, nor have I observed a copulation or an egg-mass in the open 

 air. On July 30 I observed a disposition on the part of my insects 

 to refuse food and to hide among the dry leaves. I therefore 

 selected a considerable number of tliem of both sexes for examina- 

 tion. In all, the sexual structures were immature or undeveloped. 

 In the male it was difiBcult to get the testes, because they were 

 mere empty thread-like tubes. In the females the ovaries were 

 mere bundles of tubes without even partially-developed eggs. I 

 gathered rather more than forty specimens from the trees, and 

 found the same state of affairs, except that in one specimen the 

 ova had begun to develop. This morning I selected a few fresh 

 and fat specimens — all females, as it proved — and though the 

 abdomen was much distended, the distension was caused by the 

 fully-dilated crop and stomach, and the ovaries were yet less de- 

 veloped than in any previously examined. Soon after the beetles 

 appeared in May, I examined a number of them and found that 

 in all the sexual structures were fully matured. In the males the 

 testes were quite rigid coils, which were easily removed entire, 

 while in the females the ovaries so completely filled the abdominal 

 cavity that it was impossible to open it without detaching or 

 crushing some of the eggs. The beetles earliest matured are now 

 seeking winter quarters. 



I consider my observations, now carried on for four years in 

 succession, as conclusive of the fact that at New Brunswick, N.J., 

 there is only a single brood of this species annually. I present 

 herewith figures of part of one ovary (Fig. 1) of a beetle taken 

 May 35, in which the oviduct and part of the developed eggs are 

 removed ; of the ovaries of a beetle taken July 30 on the trees, in 

 which they were best developed of all those examined (Fig. 3) ; 

 and of the ovaries of a specimen three weeks old (Fig. 3), with 

 which all the others that were examined agreed in that they were 

 at least no more developed. All the figures were made by the use 

 of a camera with a Zentmayer binocular stand, 3-inch objective, 

 a eye-piece, and drawing-board six inches from camera. The 

 vagina is not shown in Fig. 3, but is as large as that shown at the 

 base of Fig 2, and this is the only structure that has the full size. 

 I have not considered it necessary to figure the male organs, though 

 the difference between spring and summer beetles is equally 

 striking. In none that I examined did I find anything like a de- 

 veloped testicle. John B. Smith, Sc.D. 



Eutgers College, Aug. 1. 



Wheat Ru.st and Smut. 



As a general rule the Bulletins issued from the various State 

 Agricultural Experiment Stations, while not notable for the 

 amount of original matter they contain, are fairly accurate in 

 their statements, and their recommendations are to be relied upon. 

 Occasionally errors creep in, some of them the result of haste in 

 compilation, others the result of not being conversant wilh the 

 latest information on the subjects discussed. In the former cate- 

 gory must be placed the statement made in Bulletin No. 83 of the 

 Michigan Agricultural Experiment Station that wheat rust can be 

 successfully treated by what is known as the Jensen hot-water 

 method ; that is, immersing the seed in water having a tempera- 

 ture between 132° and 135° F. Wheat rust has been long under 

 investigation. It has caused a loss of about £3,000,000 sterling 

 annually in Australia, and it is safe to say that there is not a 

 country or a State where wheat is grown that has not suffered 

 from its ravages. The fact is that while wheat rust is described 

 and illustrated in the Bulletin in question, the treatment for pre- 

 vention of wheat smut is given. It is needless to say that what 

 s applicable to one is not to the other. Farmers who expect to 

 prevent wheat rust by the hot-water treatment will be sorely dis- 

 appointed. Perhaps their disappointment will result in making 

 them question, without cause, howerer. the benefits to be de- 

 rived from treating for smut. Between the two diseases there is 

 a vast difference; one (ru>t) attacks the leaves, the other (.'=mut) 

 attacks the grain. In the latter case treatment of seed will be 



