HARDWICKE'S SCIENCE-GOSSIP. 



20- 



number of pupa; produce them one after another (in 

 spite of remonstrance from myself), and twist the 

 posterior extremity of each from side to side, in order 

 to test their vitahty. The result of this may easily be 

 conjectured ; the young gentleman referred to after- 

 wards informed me, with every emergence of intense 

 disgust, that wlien the time for the appearance of the 

 perfect insects arrived, he discovered, to his horror, 

 that about eighty per cent, of them were defunct ! 

 He furthermore favoured me with the information 

 that, in his opinion, attempting to rear pupas was 

 a waste of time ! 



Even to the mere collector of insects breeding is 

 the best means of obtaining perfect specimens, and 

 it has another great advantage, viz., that it often 

 induces the collector to become an entomologist in 

 the true sense of the word, by bringing the habits of 

 insects constantly under his notice. 



Most lepidopterists have a method of keeping their 

 pupre closely allied to that which I have already 

 described, and when the cages are transferred to a 

 .greenhouse during the cold weather, so that they 

 will be secure from frost, the damping operations 

 may be continued with advantage throughout the 

 winter. 



I personally, however, prefer to allow my pupze 

 to feel the full effects of the winter, except so far as 

 ■they are protected by their cages, and when my 

 Jarvse go down beneath the mould, and enter the 

 pupae state, I often allow them to remain in the same 

 cage during the winter. 



Other later larvse can easily be reared in the cage 

 ^nd be allowed to descend into the same mould to 

 ipupate, if the collector is careful, without any in- 

 convenience ; and I may again remark that I regard 

 leaving pupae as far as possible undisturbed as an 

 item of great importance in successful breeding. 



The Rev. J. Greene, M.A. (the well-known lepi- 

 dopterist), appears to be of opinion that the removal 

 of the pups of the smaller species of lepidoptera 

 from their cocoons is advisable ("Insect Hunter's 

 Companion," 2nd edit. 1880, p. 46); but such an 

 operation would have to be conducted with great 

 care, and I am afraid, in the hands of an inex- 

 perienced collector, would probably produce fatal 

 results to the pupas. 



Taking all things into consideration, I have no 

 ■hesitation in sayihg, that, as a rule, the best and by 

 far the less troublesome course is to let the pupce 

 remain in their natural condition, except as regards 

 ■damping ; and if the collector is careful he ought by 

 this course to successfully rear a very large pro- 

 portion of them. 



"Forcing " is the name usually applied to a process 

 much in vogue with entomologists, by which the 

 imago or perfect insect is induced to emerge from its 

 pupae before the natural time. 



This result is achieved by artificial heat, generally 

 assisted by constant damping, and some species will 



readily emerge when placed under these unnatural 

 conditions, whilst, strange to say, others do not 

 appear to be influenced in the slightest degree. There 

 are many reasons why it is inexpedient to force pupae ; 

 among others, if the collector is desirous of obtain- 

 ing fertilised eggs from freshly emerged specimens 

 obtained by this means, he will, in all probability, 

 experience very considerable difficulty in inducing 

 copulation j and even if impregnated eggs are laid, 

 and the larvae hatch in due course, the buds of their 

 ■food plant will possibly not 'yet have opened, and 

 the consequence will be that the young larvce 

 will perish by starvation. 



The reader will find much valuable information 

 upon the subject of pupre in general in the " Insect 

 Hunter's Companion," and also in Dr. Knaggs' 

 "Lepidopterists' Guide." 



RECREATIONS IN FOSSIL BOTANY. 



ASTROMYELON AND ITS AFFINITIES. 



By James Spencer. 



THIS new genus of fossil plants was first de- 

 scribed and introduced to the scientific world 

 so recently as the year 1878, by Professor W. C. 

 Williamson, F.R.S., in his ninth memoir : "On the 

 Organization of the Fossil Plants of the Coal Mea- 

 sures." Fragments of Astromyelon, however, had 

 been previously described both by Mr. Binney and 

 Professor ^Yilliamson as Calamitean, on account 

 of their close resemblance to similar structures in 

 Calamites. Since the publication of the above 

 memoir, our knowledge of this interesting genus has 

 been largely increased by the discovery of a large 

 series of additional specimens, by myself and other 

 workers in fossil botany. I purpose in this paper to 

 give a short sketch 'of what is known about Astro- 

 myelon and of its nearest relations. 



The Astromyelons have been named and described 

 solely from the physiological and histological exami- 

 nation under the microscope of specimens obtained 

 from the coal-balls found in the Halifax Hard Bed 

 coal, and in a similar coal found in the neighbour- 

 hood of Oldham. In consequence of not having been 

 found in an ordinary fossil state, like most of the other 

 coal plants, very little is known about their morpho- 

 logy, that is, about the external appearance which they 

 presented when growing in their native soil. But, so 

 far as we do know about them, they appear to have 

 been for the most part small herbaceous plants like 

 Asterophyllites and the smaller kinds of Calamites. 



The Astromyelons are so frequently met with in 

 our coal-balls, where they are as common as, if not , 

 more so than, Calamites, that it is strange that they 

 have not hitherto been recorded as having been 

 found in an ordinary fossil condition, as impressions 



