January, 1907. 



KNOWLEDGE & SCIENTIFIC NEWS 



li 



building of the nests, tending- the eggs of the queen, 

 and providing nourishment for the young larvae. In 

 some species they are also effective combatants, though 

 they possess no special structures for this purpose. 



The second class, the soldiers, which includes both 

 sexes, forms from one to twenty per cent, of the inhabi- 

 tants of a colony, and is, perhaps, the most remarkable 

 feature of termitid biology. As a rule a marked differ- 

 ence exists between those of the various species, which, 

 consequently, can be distinguished by their soldiers 

 more readily than in any other way. There are two 

 very distinct kinds, those having enormous flat heads 

 and very large mandibles, and those whose heads are of 

 a more natural size, but are armed with a kind of horn 

 between where the eyes should be. These latter, 

 from their appearance, may be termed a sort of unicorn 

 variety. .Apparently there is no species with both these 

 characteristics. The soldiers in nearly every instance 

 are totally blind and wingless. The large-headed 

 variety, at the approach of danger, engage in a threat- 

 ening display in order to frighten their enemies, making 

 a rhythmic noise by hammering the ground with their 

 heads. They also attack vigorously. The unicorn 

 emits a kind of viscous fluid from his horn with which 

 he dabs his adversary. 



The winged termites or n\mphs, which can see, are 

 attracted by artificial light when the swarming season is 

 on, as is well-known to all who live in tropical countries. 

 In more temperate climates, such as Southern Europe, 

 the winged forms appear in early summer, while in 

 equatorial regions they emerge for the most part in 

 simultaneous swarms at favourable seasons, although 

 in some species they seem to be constantly produced in 

 small numbers all the year round. The object of this 

 swarming appears to be propagation. It has been 

 noted that all those going from a nest at one time are of 

 one sex. The wings are so constructed that they can 

 be shed at any moment. These winged termites are the 

 favourite food of many insects, such as the common 

 ant. Birds also and a large number of smaller animals 

 eat them ravenously. In some cases, notably in parts 

 of India and \\'est .Africa, they are used for human 

 food, and it is stated that they are digestible and 

 delicate in flavour. 



.Although millions of these insects fly abroad during 

 the swarming season, few survive the attacks which are 

 made upon them by their enemies. When a couple 

 pair off they shed their wings and then start to make 

 a new colony, becoming the King and Queen, or 

 they may be taken possession of by an orphaned colony 

 and elected to the vacant throne. The position of the 

 Royal pair is not always an enviable one, for, although 

 in some instances they appear to have their entire 

 liberty and can come and go as they please, in others 

 they are prisoners for life, their cell being usually about 

 the centre of the termitarium or in a part of the nest 

 least open to attack. They are waited on by the 

 workers, who are most careful to attend to their wants. 

 The sole duty of the Queen, who is nearly always found 

 in a gravid condition, appears to be the laying of many 

 thousands of eggs in the course of a season. .As she 

 lays them they are taken hold of by the workers and 

 carried to a more or less distant part of the nest. It has 

 been stated by some that the difference in the various 

 castes and classes can Ix distinguished in the eggs, but 

 more recent authorities have affirmed that this is not 

 so, and that probably the workers and soldiers, as well 

 a.s some of the other varieties are kept in a state of 

 arrested development by differential feeding. 



In the event of accident to the King or Queen, a 



complementary or, failing any of this variety, a supple- 

 mentary Royal individual is raised to the throne. In 

 some cases several of the required sex may be promoted. 

 These neoteinic forms, while never becoming true 

 kings or queens, are yet able to produce eggs and so to 

 continue the race. The difference between the King 

 and Queen and their offspring is in most cases so 

 marked that it appears strange that the latter should 

 have come from the eggs of this one pair. 



The termitaria in which certain varieties of these 

 creatures dwell are built up of carefully-digested por- 

 tions of earth and vegetable matter coated with a 

 liquid, emitted by the workers, which forms a hard 

 cement, so that it is possible to walk over these mounds 

 as though they were solid. 



-All termites require a certain amount of moisture, 

 some more and some less, as without this they die very 

 quickly. Certain species bore into growuig trees, 

 others again make their nests upon the branches, using 

 the living wood as food, but the majority of those who 

 do not build termitaria take up their abode in decayed 

 pieces of wood or that which has been cut down for 

 some time, and which, while not exactly wet, contains 

 sufficient moisture for their purpose. 



If white ants confined their attention to decayed or 

 rotten wood there would be little need to take steps 

 towards preventing their encroachments, but, unfor- 

 tunately, they also attack the woodwork of buildings, 

 and when once inside it is difficult and in some cases 

 impossible, to dislodge them. 



Their method is insidious, for they make merely a 

 slight puncture in the outside of the wood, while they 

 entirely eat out the interior, leaving only a thin crust. 

 Joists which were apparently sound, and floors which 

 appeared to be quite intact, have been known to 

 suddenly give way, to say nothing of the breaking-up 

 of tables and chairs owing to the attacks of these 

 insects. 



\'arious attempts have been made from time to time 

 to deal with this scourge of the tropics, with, however, 

 only partial success. The immunity which some woods 

 enjoy seems to depend largely • upon the variety of 

 termite to whose depredations they happen to be ex- 

 posed. Most kinds prefer soft piney woods, while 

 some others again seem to dislike them, though they 

 will readily attack other timljers. It has been found to 

 be quite useless to paint or cover wood with even a 

 poisonous admixture, as termites are able to even pene- 

 trate iron, glass, or mortar to get at the wood under- 

 neath. This is usually accomplished by the emission 

 of the viscid secretion used by the workers for cement- 

 ing the walls of their termitaria or subterranean pass- 

 ages, this secretion acting as a corrosive. 



Recent researches into the methods and habits of 

 these insects have proved most conclusively that the 

 only way to prevent the destruction of timber is by 

 thorough impregnation with some objectionable or 

 poisonous substance, and this view is the more em- 

 phasised as the opinion held by travellers and some 

 residents in tropical countries that if the Queen could 

 be discovered and killed the workers would disperse, 

 has now been found to be a fallacy, owing to the pre- 

 sence in the colony of neoteinic forms, which, after a 

 short time are able to take the place of the deceased 

 Royal individuals. 



Creosote and similar mineral oils have been tried, 

 but these, while successful up to a certain point, are 

 on account of their smell and for other reasons, among 

 which may be mentioned their high inflammability, use- 

 less for the timbers of dwelling-houses or for furniture. 



