326 NATURAL SCIENCE. May, 



— but it is either of a rich, raw-beefy colour or of a lowering black, the 

 difference of colour being a mark of a difference of species. On one 

 occasion a number of natives were collected together when one of 

 these giants strolled casually into the camp ; the result appears to 

 have been a rapid flight on the part of the natives. The reason for 

 the awe - inspiring character of the worm is its reputed habit of 

 sucking blood. It does not seem probable that the most recent 

 results of zoological research are known in tropical Africa ; but it is 

 a curious coincidence that this research has tended to show that 

 the line of separation between the leeches and earthworms is by no 

 means so wide as it was at one time thought to be. This big earth- 

 worm of West Africa inhabits a locality that is remarkable ; it does 

 not, as do most earthworms, burrow constantly in the ground, throw- 

 ing up castings, but lives in deserted hills of Termites. 



Another Formidable Invertebrate. 



Latrodectiis forinidahilis is an apparently well-named spider which 

 flourishes in Chili to the detriment of any human beings who have 

 rashly interfered with it. The spider is not large as spiders go ; it is 

 only lo mm. (not quite] half-an-inch) long. But, like many small 

 creatures, its malignity and venom are out of all proportion to its 

 size. Dr. Philippi tells us {Zool. Garten, vol. xxxv., no. 2), on behalf of 

 a correspondent, Herr Mohlen, that an unfortunate man, bitten by 

 the Arachnid, lost consciousness in half-an-hour, and was weak in 

 the joints for a month afterwards. Children have been known to be 

 killed by it. The pest is not a rarity either, for in a certain section of 

 country two or three webs were found in every suitable locality that 

 was examined. Another species, closely allied, lives in Spain and 

 Italy. The Chilian spider is " warningly " coloured, with two bright 

 red spots above, and two below upon its black abdomen. As we have 

 noted before. Professor F. P. Borne has an elaborate monograph on 

 this spider ; several parts have already appeared in the Actes Soc. Sci. 

 Chili. 



Continuity in Species. 



Once upon a time it was thought an obstacle to the theory of 

 Descent in general, and to evolution by means of Natural Selection in 

 particular, that the gaps existing between genera and between species 

 were so hard to bridge over. Connecting links were absolutely 

 demanded by the theorisers, but the working naturalist was unable to 

 supply them. Let us not be misunderstood ! We do not refer to 

 intermediate forms between the larger groups, for these the 

 ingenuity of morphologists soon discovered to exist in almost 

 embarrassing profusion, nor do we refer to such interesting series 

 as that furnished by the ancestors of the horse ; but we refer to 

 those minute gradations of form, each inappreciably different 



