4 Transactions of the Society. 



egg is almost completed within the body of the living mother, and 

 that the egg is extruded, certainly as an egg, as in the first method, 

 but with the larva so fully developed that it escapes from the ovum 

 very shortly after deposition. 



I have a strong suspicion that a third mode, only to be found 

 in exceptional instances, is that which Huxley states to be charac- 

 teristic of the family, viz. that the female is viviparous or ovo- 

 viviparous. This, if it occur at all, is probably not the case at all 

 seasons of the year, even in the species where it may take place 

 during the period of most rapid reproduction. I have not any 

 proof or certainty that this mode ever exists, for I have not ever 

 witnessed the birth of a living larva, unenveloped in any egg-shell, 

 from any of the Orihatidm, but I have dissected out of the body of 

 a female, either hving, or killed immediately before, a larva, which, 

 although not sufficiently strong or active to run, has been fully de- 

 veloped, and able to kick its legs and move its trophi in a very 

 vigorous manner, and exhibit other signs of life. In addition to 

 this, I have several times found larvae in a cell where I had kept a 

 pair of adults, and which I had carefully examined for ova a short 

 time before without detecting any. I do not place much reliance 

 upon this last reason, as the ova are sometimes extremely difficult 

 to find in consequence of their smallness, their want of colour,^ and 

 the places in which they are laid ; but, as far as it goes, it is in 

 fevour of the occasional viviparous theory. 



In the above-named three methods only one, or at the utmost 

 two eggs are matured at one time ; the reason for this is evident 

 enought as the egg is so large as to appear disproportionate to the 

 size of the body, and many could not be ripe at once consistently 

 with the hfe of the Acarid. 



I believe that the fourth method has not hitherto been 

 recorded by any observer, and it appears to me interesting. I 

 have noticed it chiefly in the case of Orihata globula, but it pro- 

 bably exists in other species. It is as follows: The female, 

 instead of maturing only one or two eggs at the same time, 

 matures a much larger number, often a dozen or more, so that the 

 abdomen appears to be entirely filled with them ; these eggs are 

 not laid, neither do they hatch within the body of the Hving 

 mother, but the mother dies with the abdomen distended by fully 

 formed 'eggs, in which the larvae have not been developed. The 

 whole contents of the abdomen except the eggs seem to dry up 

 and disappear, leaving the chitinous shell of the parent as a pro- 

 tection to the ova. This condition of matters often lasts for a 

 considerable time, indeed I believe that Orihata globula often, or 

 usually, passes the winter in this state. When the larvae are at 

 length hatched, they escape by the opening of the camerostomum, 

 the labium having probably dropped off, or by the genital or anal 



