444 Proceedings. 



he pointed to the diagram of the Lyttelton gauge, and showed how it failed 

 at the critical moment at the time of the Krakatoa disturbance, when the 

 sea-level receded to at least three feet below the lowest water previously 

 recorded. What was wanted, therefore, was a cheap simple tide-recorder, 

 and plenty of them, at every lighthouse and every suitable point round the 

 coast ; and the result would be the accumulation of records that would have 

 extreme value for future reference. 



After much consideration, he had arrived at the form now exhibited, 

 which was an adaptation of compound diagonal levers that moved vertically 

 above and below a fixed point, the difference in the number of parallelograms 

 above and below this point determining the degree to which the scale of 

 motion is reduced, by an automatic pen marking a diagram on paper carried 

 forward by clockwork. The model and drawings were then fully explained, 

 and the hope expressed that before long this instrument or a similar one 

 would be extensively used. 



2. " Extraordinary Discovery regarding Generation in In- 

 sects," by W. M. Maskell, F.M.S. 



In the " Comptes Eendus des Seances de 1'Academie des Sciences" for 

 February, 1887, M. Moniez announces a discovery of the greatest interest 

 regarding generation in certain forms of life, and the so-called "partheno- 

 genesis." Lecanium hesperidum, a Coccid or scale-iusect very common in 

 Europe and in New Zealand, has been known and studied most carefully for 

 nearly two centuries without the discovery of any male insect. Amongst 

 others, since Linnaeus, who first observed the insect scientifically, Leydig and 

 Leuckart, two German biologists of note, made very minute researches for the 

 male without result. " Parthenogenesis," or the reproduction without male 

 agency in every case, has long been known to obtain, for example in the 

 Aphides, to some extent ; that is to say, several generations occur in that 

 family without sexual intercourse. But the male Aphides are known to 

 exist ; and, as far as information at present extends, this " parthenogenesis" 

 only avails for a very limited series of generations, probably not more than 

 eleven. In Lecanium hesperidum, however, the generations, apparently 

 through female agency alone, were thought to be countless and unlimited ; 

 self-fecundation seemed to be the rule in this species. An additional pecu- 

 liarity was given to this by the fact that in most of the other Coccids males 

 were found, and, in the species where the male was not known, probably 

 want of full observation quite accounted for its absence. The propagation 

 of Lecanium hesperidum was therefore up to the present time a problem 

 unsolved by the most careful inquiry, and apparently insoluble. 



M. Moniez has, to a great extent, discovered the solution, but it is 

 perhaps not too much to say that his explanation reveals a process even 

 more extraordinary than " self-fecundation." He announces that he has 

 discovered the male of Lecanium hesperidum, and that it exists entirely 

 within the body of the mother ; not only so, but that it undergoes in that 

 position the same three metamorphoses as any other insect, having a larval. 

 a pupal, and an "imago" stage: not only so, but that its sexual organs 

 appear, and its spermatozoa are matured, in the second or pupal stage, 

 before the appearance of the other members of the body. In the absence of 

 eyes, and the tenderness of its non-chitinous skin, the male differs from the 

 female larva; found with it also within the mother's body : in the absence of 

 wings, it differs altogether from all the other males of the Coccid family. 



Further, if I understand rightly the summary which I have seen of M. 

 Moniez 's paper, these curious male insects, as they never leave the body of 

 the maternal Lecanium, perform their sexual functions necessarily therein. 

 I, follows from this that a female Lecanium must be impregnated in its 

 earliest, or larval, stage (for in that alone, besides as an egg, is she within 

 t e body of the parent) : and, consequently, that the effect of the action of 

 t e male spermatozoa must remain dormant in the female larva after it 



