Feb. 19, 1 8 74 J 



NATURE 



309 



and of their habits, is now published in Germany ; never- 

 theless few Englishmen will have as yet seen the 

 account. 



In the German paper he justly compares, as far as func- 

 tion is concerned, the winged males and females of the 

 one form, and the wingless males and females of the 

 second form, with those plants which produce flowers of 

 two forms, serving different ends, of which so excel- 

 lent an account has lately appeared in NATURE by his 

 brother, Hermann Miiller. 



The facts, also, given by Fritz Miiller with respect to 

 the stingless bees of Brazil will surprise and interest ento- 

 mologists. Charles Darwin 



Feb. 1 1 



" For some years I have been engaged in studying the 

 natural history of our Termites, of which I have had more 

 than a dozen living species at my disposition. The several 

 species differ much more in their habits and in their ana- 

 tomy than is generally assumed. In most species there 

 are two sets of neuters, viz., labourers and soldiers ; but 

 in some species {Cnloicnncs Hg.) the labourers, and in 

 others {Anoplotenncs F. M.) the soldiers, are wanting. 

 With respect to these neuters I have come to the same 

 conclu'-ion as that arrived at by Mr. Bates, viz. that, diffe- 

 rently from what we see in social Hymenoptern, they are 

 not modihed images (sterile females), but modified larvje, 

 which undergo no further metamorphosis. This accounts 

 for the fact first observed by Lespes, that both the se.xes 

 are represented among the sterile (or so-called neuter) 

 Termites. In some species of Calotcrmcs the male 

 soldiers may even externally be distinguished from the 

 female ones. I have been able to confirm, in almost all 

 our species, the fact already observed by Mr. Smeathman 

 a century ago, but doubted by most subsequent writers, 

 that in the company of the queen there lives always a 

 king. The most interesting fact in the natural history of 

 these curious insects is the existence of two forms of ssxual 

 individuals, in some (if not in all) of the species. Besides 

 the wmged males and females, which are produced in vast 

 numbers, and which, leaving the termitary in large 

 swarms, may intercross with those produced in other 

 communities, there are wingless males and females, which 

 never leave the termitary where they are born, and which 

 replace the winged maie^ or females, whenever a com- 

 munity does not find in due time a true king or queen. 

 Once I found a king (of a species of Eutenncs) living in 

 company with as many as thirty-one such complemental 

 females, as they may be called, instead of with a single le- 

 gitimate queen. Termites would, no doubt, save an extraor- 

 dinary amount of labour if, instead of raising annually 

 myriads of winged males and females, almost all of which 

 (helpless creatures as they are) peiish in the time of 

 swarming without being able to find a new home, they 

 raised solely a few wingless males and females, which, 

 free from danger, might remain in their native termitary ; 

 and he who does not admit the paramount importance of 

 intercrossing, must of course wonder why this latter 

 manner of reproduction (by wingless individuals) has not 

 long since taken the place through natural selection of 

 the production of winged males and females. But the 

 wingless individuals would of course have to pair always 

 with their near relatives, whilst by the swarming of the 

 winged Termites a chance is given to them for the inter- 

 crossing of individuals not nearly related. I sent to Ger- 

 many, about a year ago, a paper on this subject, but do 

 not know whether it has yet been published. 



" From Termites I have lately turned my attention to a 

 still more interesting group ol social insects, viz., our 

 stingless honey-bees (Melipona and Trigona). Though a 

 high authority in this matter, Mr. Frederick .Smith, has 

 lately affirmed, that " we have now acquired almost a 

 complete history of their economy," I still believe, that 

 almost all remains to be done in this respect. I think 

 that even their affinities are not yet well established, and 



that they are by no means intermediate between hive- and 

 I humble-bees, nor so nearly allied to them, as is now gene- 

 rally admitted. Wasps and hive-bees have no doubt 

 independently acquired their social habits, as well as the 

 habit of constructing combs of hexagonal cells, and so, I 

 think, has Melipona. The genera Apis and Melipona 

 may even have separated from a common progenitor, 

 before wax was used in the construction of the cells ; 

 for in hive-bees, as is well known, wax is secreted on 

 the ventral side : in Melipona on the contrary, as I have 

 I seen, on the dorsal side of the abdomen ; now it is not 

 probable, that the secretion ofjwax, when once established, 

 should have migrated from the ventral to the dorsal side, 

 or vice versa. 



" The queen of the hive-bee fixes her eggs on the 

 bottom of the empty cells : the larvse are fed by the la- 

 bourers at first with semi-digested food, and afterwards 

 with a mixture of pollen and honey, and only when the 

 larva; are full grown, the cells are closed. The MeliponEe 

 and Trigonn?, on the contrary, fill the cells with semi- 

 digested food before the eggs are laid, and they shut the 

 cells immediately after the queen has dropped an egg on 

 the food. With hive-bees the royal cells, in which the 

 future queens have to be raised, differ in their direction 

 from the other cells ; this is not the case with IVIehpona 

 and Trigona, where all the cells are vertical, with their 

 orifices turned upward, forming horizontal (or rarely 

 spirally ascending) combs. You know that honey is 

 stored by our stingless bees in large, oval, irregularly 

 clustered cells ; and thus there are many more or less 

 important differences in the structure, as well as in the 

 economy, of Apis and Melipona. 



" My brother, who is now examining carefully the ex- 

 ternal structure of our species, is surprised at the amount 

 of variability, which the several species show in the 

 structure of their hind legs, of their wings, (S;c , and not 

 less are the differences they exhibit in their habits. 



" I have hitherto observed here 14 species of Melipona 

 and Trigona, the smallest of them scarcely exceeding 2 

 millimetres m length, the largest being about the size of 

 the hive-bee. One of these species lives as a parasite 

 within the nests of some other species. I have now, in 

 my garden, hives of 4 of our species, in which I have 

 observed the construction of the combs, the laying of the 

 eggs, &c., and I hope I shall soon be able to obtain hives 

 of some more species. Some of our species are so elegant 

 and beautiful and so extremely interesting, that they would 

 be a most precious acquisition for zoological gardens or 

 large hot-houses ; nor do I think that it would be very 

 difficult to bring them to Europe and there to preserve 

 them in a living state. 



" If it be of some interest to you I shall be glad to give 

 you from time to time an account of what I may observe 

 in my Melipona apiary. 



" Believe me, dear Sir, &c., 



" Fritz Muller" 



IN the previous article were mentioned some of 

 Professor Kaiser's conclusions. We are induced 

 to add a few further remarks, from their general 

 applicability. The delineation of the heavenly bodies, 

 he says, is always a very difficult task, especially when, 

 as in the case of Mars, we have to deal with fea- 

 tures more or less indistinct, delicately and gi'adually 

 shaded. With the most powerful telescopes the disc is 

 but small ; and on it we find a mass of ill-defined and 

 frequently very feeble spots, which require close attention 

 for their disentangleinent, and it is hard to obtain a clear 

 conviction as to the outlines and shadings that have to 

 be drawn. The difficulty is much increased by the inces- 



* CoutiiiueJ from p. 289. 



