NOTES ON MELICERTA EINGENS. 247 



daring the coming winter students who have access to them will break 

 up with a couple of fine needles some tubes of Melicerta, they will 

 find that a very few will contain a hving female rotifer. She may have 

 some eggs with her in the tube, but more probably she will have none. 

 If the tube contains no female rotifer, then it will probably, in about 

 one out of five instances, be found to contain either eggs or developed 

 males, or perhaps both. In the very first tube I opened the female had 

 gone, devoured by her offspring perhaps, but there were four of these free 

 swimming rotifers. They were very lethargic, and seemed startled by 

 my rude intrusion. One or two of them were hke eggs struggling into 

 life. I found them in every stage short of real activity, and in one 

 or two specimens I found them incompletely developed and associated 

 with ordinary female eggs, a fact which showed that the developed 

 specimens were not visitors to the tubes, but were bi*ed and born there. 

 The way to recognise a male egg in M. ringens is to look for the mastax. 

 The fact that the male has a mastax leads me to think that for a time it 

 is in a state of growth, and that the spermatic secretions are not ripe 

 until it has left the parent some hours, or perhaps days. It is possible 

 that then the mastax and stomach may dwindle into insignificance, 

 while the other organs increase in importance. The difliculty of following 

 particular individuals will make it by no means easy to learn its whole 

 life history. The mastax is developed very early, while the egg is in 

 the womb of the mother. In examining some sUdes of dissections 

 of the mastax of 31. ringens, presented to me by the Eev. Lord Sydney 

 Godolphin Osborne, and lately exhibited at the Royal Microscopical 

 Society on the reading of a recent paper there, I found that on one slide 

 there were six eggs, and that one of these exhibited a mastax in a 

 forward state of development, and I beheve it is a male egg. That the 

 male should have a mastax at all is singular, as usually these males are 

 mere spermatic bags, without mouth or stomach, very active and hvely, but 

 apparently requiring no food at all. But the mastax of the male Melicerta 

 is very easily recognised ; it differs from that of the female in being much 

 more angular ; it is shaped something hke a W inverted ; it is a very busy 

 organ, and even protrudes at times from the disc itself. The facts 

 above stated support the view that the tube of Melicerta is not only a 

 protection to the animal when living, but harbours the eggs when the 

 animal dies ; while they also lead me to think that the time to seek the 

 male is the end and beginning of the year. 



With respect to the act of coition, that must be no doubt usually 

 concealed by the tube, but we i-ecognise what a deUcate sense of 

 touch these rotifers must possess, when we reflect that they are 

 able to recognise the salutation of the suitable male, and that they 

 permit it to have access to the tube. The remarkable disproportion, 

 again, in the size of the male rotifers deserves attention ; large male rotifers 

 would be quite useless as they simj^ly could not enter the tube. We see, 

 too, that the absence of stomach and mastax in some, and the diminiation 

 of the size of these organs in others, leave room for an increased supply 

 of the more important secretions. What Melicerta, for instance, requires 

 as essentials in her male is a size which shall be in inverse pi'oportion to 



