112 



Selections. 



[NO. 5, NEW SERIES, 



tlienogenesis, phenomena of a totally different nature are exhibited 

 — phenomena, the belief in the occurrence of which, did it rest on 

 individual or questionable testimony, would gain but slight assent 

 among the learned, but when we find such an array of names of 

 naturalists who have mainly contributed to the advancement of 

 natural science, all bearing testimony to the facts as related by 

 Siebold, we cannot withhold our belief, that in many cases perfect 

 offspring can arise " sine concubitu," from animals fitted for a 

 union of the sexes, and that in one species of insects at least the 

 sex of the offspring depends on the entrance of spermatic filaments 

 into the egg. 



In the study of this most interesting work, we are struck with 

 the circumstance, that science is often retarded by general or 

 sweeping assertions, although emanating from high authority. 

 When Castellet, in 1795, reported to Reaumur, that he had found 

 that a moth of Bombyx mori (silk-worm) laid perfect eggs, though 

 unimpregnated, he received the laconic reply — " ex nihilo nihil 

 fit." How different in a similar case was John Hunter's reply — 

 " But did they hatch ?" for naturalists have not long been familiar 

 with the circumstance that unimpregnated females will sometimes 

 lay eggs ; but these have hitherto been supposed to have been in- 

 variably incapable of being developed into a perfect animal. A 

 common example of this is the occurrence of pullets' eggs, but 

 these are notoriously incapable of being developed by incubation. 

 At first blush we might be led to infer that reproduction without 

 fecundation was impossible, so contrary does it appear to the usual 

 course of nature, both in the vegetable and the animal kingdom. 

 "We observe what careful precautions are taken that the sperma- 

 tozoa should reach their proper nidus uninjured : how many pro- 

 visions are found to hedge around the safety of the pollen ! Ex- 

 ceptional cases, however, do occur in the vegetable kingdom. The 

 Caelebogyne, for instance, a dioecious plant from Australia, has 

 produced fertile seeds at Kew, although the female only is known 

 to botanists ; and M. Lecoq had deduced from some experiments 

 of his own, that similar phenomena occur sometimes in hemp, 

 spurge, &c. Our author seems to have been fully aware of the 



