Earthworms and their Allies

worms, and probably due to the direct interference of man. Thus we find in collections of earthworms from various parts of the world not o

om the three parts of the world mentioned, and also from Hawaii. Others have increased its known range to other parts of the South American continent, to Central America, the West Indies, the islands of Sumatra, Java, Borneo, Celebes, Mauritius, and Madagascar, etc. It is in fact found everywhere in the tropics. With this range may be contrasted that of another genus of the same family (Geos

this genus, it will be well to survey the whole group of Oligochaeta and to reduce t

nyms of the name originally given by Kinberg who however did not recognise the distinctness of the form as a genus. It is now known as Eudrilus eugeniae. The variety of names given to supposed different forms (for two of which I am myself responsible) is due to the fact that in earlier days when nothing was known about the geographical distribution of this group of animals it was thought by no means unreasonable that a given genus represented by seve

indeed one or two forms, e.g. Criodrilus and Glyphidrilus, which have a considerable range though not nearly equalling that of Eudrilus and Pontoscolex. These are, howeve

le way in other eastern regions; there is, however, one species, Moniligaster bahamenis, described some years since from the Bahamas which must

ies which apparently possess the same facilities for making their way in different

altogether. In addition to these are some perhaps more questionable instances, such as the genus Gordiodrilus which, prevalently West African, has also been found in the West Indies, in East Africa, and in India and Madagascar. These instances I propose to leave out of consideration in the present sketch. The most obviously peregrine genus of all those enumerated is Pheretima, which according to my experience turns up in almost all gatherings of earthworms from any part of the tropical or even sometimes temp

e species P. biserialis, P. capensis, and P. hawayana. The synonymy of the different species of this large genus is not yet in a completely settled condition. But in the meantime it is in my opinion quite possible that both P. hesperidum and P. californica are identical with species also occurring in the East. There remains the somewhat doubtful P. elongata from Peru which has not been very fully described. There is thus no convincing evidence of spe

e also included in the list from South America, and that many of them are also found in other parts of the world, and nearly all of them in the East. There remain a few which are doubtful. It is quite possible that P. mauritiana is the same as P. hawayana and P. bermudensis, in which case it has a world-wide range. P. taprobanae is well known as a Ceylon

al America, one to Hawaii, one to Madeira, one to Algeria, while the remaining two are found pretty well over the whole surface of the world. More recently the same authority has somewhat extended his view of the generic characters, so as to include a number of forms found in Patagonia, Cape of Good Hope, and the antarctic region generally, while he has lumped together into two species only, viz. M. phosphoreus and M. dubius, the eleven forms just mentioned, which species therefore are abs

number of peregrine forms and that these are most abundant in collections from extra-European countries, where the collector has searched in cult

ailed in some cases than in others. It remain

mily Megascolecidae are very much more numerous than those of the Eudrilidae or even the Geoscolecidae, the fact that there are more peregrine Megascolecidae will lose some of its importance. With the Lumbricidae the case seems to me to be different. Here the preponderance, not only in species (relatively speaking) but in individuals, is much above that of other families.

in Europe; it is in fact circummundane in the tropical zone, as is also Pontoscolex. Dichogaster bolavi is again a trifle more restricted in its range, having been recorded from tropical Africa, South America, West Indies, Madagascar, and India. Its occurrence near Ham

said that these peregrine species are marked by any great variability of structure as compared with other forms, which might allow for their suiting themselves to various climates and conditions. It is true that Eudrilus eugeniae has received many names which might at first argue some variability. But these names have been perhaps given by persons rather under the influence of the idea that remote habitat implied specific difference, and who

tablished itself in Europe, from which country indeed it was early known as an apparently indigenous inhabitant. We must put this and some similar cases down to ability to do without great heat. It is probabl

y imported thither from many quarters of the globe, among which I described some eighteen or twenty new species including, for instance, the African genus Gordiodrilus. There are plenty of facts of a similar nature and Dr Michaelsen has pointed out that botanical gardens act as centres of dispersion for accidentally introduced Oligochaeta. We must therefo

e new countries. But it is obvious that this is not of itself a sufficient cause to explain the facts. Otherwise this count

ection. For it is above all the Lumbricidae, normally dwellers in temperate climates, that are so remarkable for their wide range over the world. Nor can it be convincingly asserted that the extra-Palaearctic Lumbricids ar

indigenes or not remains perhaps a matter for discussion; but it is at least noteworthy that the vast preponderance of species occurring there are also European and even British. In this particular case, which is on the whole the most emphatic of all the cases of peregrine earthworms, some explanations are possible, or at least have been offered. In the first place it would appear that earthworms are more abundant as individuals in northern countries where the soil is rarely dry for prolonged periods. And as has been already pointed out there is a close relation between earthworms and agriculture. Dunghills are fertile gathering grounds for some species, and ploughed f