464 



FARMERS' REGISTER— FECUNDITY OF INSECTS, &c- 



For the Farmers' Regisler. 

 FECUNDITY OF INSECTS. 



A calculation was submilied in No. 6, (p. 329) 

 of Uie Farmers' Re<4-ister, to show tiiat two hun- 

 dred millions of moth weevil might he produced in 

 successive o-cnerations from the eggs of a single, 

 pair, during the v/arm season of one year. The 

 estimate was founded on the supposition that each 

 pair produced two iiundred eggs, and that one 

 month was sufiicient for tlie {)roduction and ma- 

 turing of each generation. The nundicr of egg-s 

 supposed to 1)0 deposited by a (ijmalc weevil will 

 not be considered very unusual, and tl;e estin)atc 

 therebv exaggerated, if we judge by comparison 

 with nianyolher insects which ))ropagate by ])airs, 

 even if we pass over the more remarkable cases 

 of such females as singly produce a \\ hole swarm 

 or race, as the queen" bee, and the queen oi the 

 white ants. The following facts of this kind are 

 selected from the work on' the Transformation of 

 Insects, which forms part of the Library of Useful 

 Knowledge. 



"A common fly will lay 144 eggs— a 



spider 170. I have seen a hydrachna produce 600 

 eggs, and a female moth 1100." — " A gall insect 

 has laid 5,000 eggs" — '' and 10,000 have been 

 found in the ovaryVor what is supposed to be that 

 part, of an ascarides." — " An insect very similar 

 to an ant (mutilla 1) has produced 80,000 in a sin- 

 gle day." — " It is this extraordinary fecundity 

 which, under favorable circumstances, produces 

 countless swarms of insects, that give origin to 

 the opinion of their being spontaneously genera- 

 ted by putrefaction, or brought in some mysterious 

 Avay by blighting winds." pp. 47, 48. An earlier 

 passage is as follows : " In the case of the aphides, 

 also, the fecundity is almost incalculable. Reau- 

 mur proved by experiment, that one aphis may be 

 progenitor of 5,904,900,000 descendants during its 

 life ; and Latreille says, a female during the sum- 

 mer months usually produces about 25 a day. 

 Reaumur further supposes that in one year there 

 may be 20 generations." p. 19. The female of the 

 common gnat {Culex pipiens, Linnjeus,) depo- 

 sits her eggs in a connected body so as to form a 

 kind of boat or raft which floats securely on the 

 water where the mother places them, and they 

 vary in number from 250 to 350, pp. 72, 74. One 

 kind of flesh-fly (Sarcophuga carnaria, Meigen) 

 is viviparous, that is, it hatches its eggs in an ab- 

 dominal pouch, and instead of eggs, deposits mag- 

 gots on dead carcasses." — " The arrangement of 

 the numerous minute larva; in tlie pouch is very 

 remarkable, and resembles the coil of a watch- 

 sj)ring, or a roll of ribbon. Reaumur had the 

 patience and perseverance to uncoil this nmltitudi- 

 nous assemblage of flies in end^ryo, and found it 

 about two inclies and a half in length, though the 

 body of the mother fly herself was only about one 

 third of an inch, and he computed that there were 

 about 20,000 young in the coil." pp. 110, 111. 

 The queen of the white ants of (Termites,) Hin- 

 doston, as before observed, cannot be cited as an 

 ordinary case of fecundity, she being the only fe- 

 male of her tribe, and designed by nature to be the 

 mother of a countless race : but as the most won- 

 derful instance of insect fruitfulness, I willstatethe 

 opinion of Smeathman that this female " lays 60 

 eggs in a minute, which will amount to 86,400 in 

 a day, and 31,536,000 in a year," p. 15. 



memorakda of crops made in 1789. 



The following memoranda of "old times" in Virgi- 

 nia, may be intc-esting to some of our readers. The 

 statement, (which seems to have been written at the 

 ume wlien the crops were made,) was furnished forpub- 

 lication in the Farmers' Register by Richard Randolph, 

 Esq. of York, Va. 



Raised by William Johnson, overseeer to Rich- 

 ard Randolph, of Curies', Henrico county, Va. in 

 the year 1788, from 36 acres of ground, 14 of 

 which tilled, viz : 



Raised by Col. Francis Lightfoot Lee, of Mana- 

 kin, King William county, in 1789, from 49acres 

 of land, (37 tilled.) 

 112 barrels Indian corn, - at 18s. £100 16 

 150 bushels wheat, - - 10 75 



360 — barley, - - 3 54 



500 — potatoes, - 16 



A large quantity pumpkins, worth 

 Some turnips, supposed 



£274 6 

 Teste, 



WM. CARTER, of Shirley, Va. 

 The corn blades should be valued, in addition to 

 the above. 



UNDULATING RAILWAY. 



[In a former number of the Farmers' Register we 

 pi-esented a view of the plan and theory of undulating 

 railways, and now are enabled to add the following 

 statement of practical experiments, made to test the 

 truth and value of the theory ] 



A series of experiments have been sometime in 

 progress, on a part of the Liverpool and Manches- 

 ter railway for the purpose of ascertaining the 

 practicability of a scheme suggested and very 

 strongly entertained by Mr. Badnall, of impelling 

 carriages upon a railway by means of a power de- 

 rived from the inequalities or undulations of the 

 line. The directors of the railway liberally al- 

 lowed Mr. Badnall the use of two engines, the 

 Rocket and the Caledonian, and though the tem- 

 porary defects of the former engine dkl not at first 

 allow of the experiments being carried to the cer- 

 tainty that the projector desired, they were yet am- 

 ply sufficient to justify his confidence in the prin- 

 ciple. " I consider," says Mr. Badnall, " the re- 

 sults in practice to confirm most fully the advan- 

 tages shown on the models, and I have not the 

 slightest doubt that it will be found practicable to 

 convey far greater loads from one summit of a 

 curve to another, whose angles do not even exceed 

 that of the Sutton inclined plane, than any locomo- 

 motive engine can move upon a level road." 



