NOTES AND MEMORANDA. 453 



water becoming rejuvenised into an immense number of uni- 

 ciliated zoospores; during prolonged drought, on tbe other 

 hand, passing down into the subterranean root-ramifications, 

 and there breaking up into a number of root-cells, surrounded 

 by a special membrane, these becoming modified either into 

 s ubterranean zoosporanges, or directly into vegetative plants, 

 or into rooted hypnosporanges. Hypnosporanges black-olive- 

 green, globular, the neck portion of the root having the wall 

 thickened almost to the closing up of its cavity, for a long 

 distance simple, secondary ramifications sparing, thin-walled 



W. Archer. 

 Motility of the Spermatozoids of Limulus. — Through the 

 kindness of Mr. Carrington E.L.S. of the Westminster Aquarium, 

 I received some mouths since a specimen of the American King 

 crab in the liviug condition. My principal object was to study 

 the colouring matter of the blood. Concerniug it 1 will here 

 only remark, that the blood when first shed is almost colourless 

 having but a faint opalescence of a blueish tint. This however, 

 rapidly gives way to a blue colour which increases in intensity 

 for three hours after the blood has been shed, and finally attains 

 a deep indigo tint. The colour is due either to the chemical 

 change, or to the solution of, a substance contained in the cor- 

 puscles. The specimen from which I collected the blood was 

 fortunately a male, and was in the full vigour of tlie breeding 

 season. A quantity of white cream-like sperm was discharged 

 by the animal from the orifices of the seminal ducts, placed on 

 the protected surface of the opercular plate. I was thus able to 

 examine some of the spermatozoa in the mature and living con- 

 dition. The simple fact which I wish now to record and which I 

 believe has not been previously recorded is, that the spermatozoa 

 of Limulus are actively motile. They are, like the other histo- 

 logical elements of that animal, of very large size. Each 

 presents a lemon-shaped head provided with a delicate tail of 

 great length. At the moment of writing I am unable to lay my 

 hand on the measurements. The vibratile character of the tail is, 

 however, the important matter. Thousands of the spermatozoids 

 were seen swarming together on the field of the microscope, whilst 

 the travelling of isolated individuals over considerable distances 

 was watched. 



Any fact, however small, which bears upon the question of the 

 affinities of Limulus is important. Usually Limulus is considered 

 as an Entomostracous Crustacean ; by some naturalists it is placed 

 in a class alone, in close relationship wdth the other branchiferous 

 Arthropoda, others again would associate it most intimately with 

 the Arachnida and in fact with the Scorpions. The spermatozoids 

 pf the various classes of Arthropoda have, so far as they have been 



