394 FRIEND: ON HYBRIDITY AMONG WORMS. 
If we add that the common species is capable of copulating with two 
of the foregoing, we get in addition :-— 
4) Lumbricus terrestris + rubellus. 
(5) Lumbricus terrestris + rubescens. 
The next question is—Do such crosses ever occur in nature ? 
I have been fortunate enough to observe recently a very interesting 
case, which enables me to give an affirmative answer. 
I was walking during Easter week through some fields in the 
suburbs of Bradford, when my eye alighted on an old piece of 
sackcloth decaying in a ditch. The worm-hunter should never pass 
a thing of this kind indifferently: I have found my richest treasures 
under such materials. This was the case here. Suddenly lifting the 
rotten sackcloth, I observed a pair of worms in close juxtaposition. 
I had sufficient time to observe the nature of their relationship 
before they withdrew into their burrows, from which I instantly 
belong to two distinct species. They were so nearly of a size, colour, 
shape, and general appearance, that they would inevitably have passed 
as one and the same species had I not recently worked out their 
characters, and identified them before they withdrew. On exhuming 
their bodies, I found them not only sexually mature, but one 
(Z. rubescens Friend), representing a species new to science, had on its 
ventral surface three spermatophores filled with life-germs. 
The two species are closely allied, and yet perfectly distinct. Their 
differences are few, but well-marked, and may be thus expressed :-— 
L. rubellus Hoftm. L. rubescens Friend. 
Male pore hidden. Male pore on papillz. 
Girdle, 27-32. Girdle, 34-39. 
Tubercula pubertatis, 28-31. Tubercula pubertatis, 35-35- 
No preclitellian papillz. Papille on segment 28. 
differences to determine a case when observed. I am further 
convinced that patient research in this direction will yield results of 
the utmost importance in their bearing upon the evolution of those 
indigenous species of worms which are now usually placed under the 
genus Allolobophora. I have side-lights on this subject from another 
quarter, which I must not at this moment introduce. 1 
Naturalist, — 
