198 



NATURE 



\yan. II, 1872 



books. But who reads blue-books ? Farmers cannot 

 perform successfully a feat which almost baffles the best- 

 trained member of Parliament. What they want is a 

 Department of Agriculture which shall improve the laws 

 of the land, as well as investigate obscure subjects, 

 and circulate the official reports in the manner of 

 the United States department, in editions of a quarter of 

 a million. The United States Commissioner not only 

 expounds the laws of the federation on roads, fences, 

 &c. ; but he learns, for instance, that the beet sugar industry 

 of Europe, and the system of agricultural education in Ger- 

 many and other countries, present instructive features to 

 the intelligent agriculturist, and he therefore sends a quali- 

 fied commissioner to report on each of these subjects. 

 American farmers are thus enlightened on European 

 agriculture sooner and more authoritatively than we, who 

 are separated from the Continent by nothing more than a 

 " streak of silver sea." There are our Colonies also ; 

 and we would on their behalf inquire whether an intend- 

 ing emigrant to Canada, New Zealand, Australia, or the 

 Cape, can obtain as much reliable information on their 

 agriculture as the American farmer now possesses about 

 his country's recent purchase, Alaska ? It thus seems 

 clear that the United States Department of Agriculture 

 presents features which may be profitably copied by our 

 Executive Government, and others which are equally 

 instructive both to our agriculturists and to our men of 

 science. 



ACASSIZ'S SEASIDE STUDIES 



Seaside Studies in Natural History. By Elizabeth and 

 Alexander Agassiz. Marine Animals of Massachusetts 

 Bay: Radiates. 2nded. (London: Triibner & Co., 1871.) 



THIS is a reprint, with a few additions, of the charming 

 work which became so popular in America and in 

 England some five years since on account of its intrinsic 

 merits .and the beauty of the illustrations. The book 

 includes descriptions and more or less truthful illustrations 

 of the Actiniae, Madreporaria, Alcyonince, Acaleph.-e, 

 Hydroids, Holothurians, Echinoidea, and Asteroidea which 

 may be found in the neighbourhood of Massachusetts Bay. 

 The history of the development of many of the forms is 

 carefully written, and is obviously the result of patient 

 original observation. 



In noticing the reproduction of the Actiniae the authors 

 remark that the eggs which hang on to the inner edge of 

 the partitions of the visceral cavity drop off into it during 

 different stages of development. Ordinarily they are 

 passed out through the mouth as Planula-shaped ciliated 

 creatures, which soon become attached to a foreign sub- 

 stance. The base enlarges, and the free extremity falls in 

 to form a concavity, the future gastric and visceral cavity. 

 But sometimes the embryo is provided with tentacles and 

 with its stomachal cavity before it escapes. Lacaze- 

 Duthiers has described a similar state of things in the 

 reproduction of Coj-allium rubrum, and probably the 

 embryonic condition of all the stony corals is that of a free 

 swimming sac which undergoes metamorphosis. These 

 usually sedentary Actinia: are not without nomadic species, 

 and AracJiiiadis brachiola A. Ag. is described as a small 

 floating anemone, very nocturnal in its habits, which swims 



with its tentacles and mouth downwards, using the body as 

 a float. This form is not quite symmetrical, and has an 

 evident tendency towards establishing a longitudinal axis. 

 The mouth is out of the centre. Bicidium is noticed as 

 selecting the mouth-folds of the common large red Cyanea 

 as its home. It undergoes retrograde development, and 

 its tentacles are short and stout on account of its parasitic 

 existence. 



The only stony coral described is the littoral Astrangia, 

 which is probably a descendant of the miocene forms 

 which once flourished on the same area. The tentacles of 

 this coral are covered with wart-shaped masses, crowded 

 with nematocyst lasso cells. Such forms as Caryophyllia 

 and Balanophyllia, which are so well represented on our 

 coasts and in thirty fathom water, do not appear to have 

 been found by the authors in Massachusetts Bay. 

 Amongst the Acalephs, Cyanea, of course, is well 

 described, and it is observed that so large a portion of its 

 bulk consists of water that one of no less than thirty -four 

 pounds weight being left to dry in the sun for some days, 

 was found to have lost 99 per cent, of its original weight. 

 Writing of the not very attractive appearance of these 

 huge jelly fish, Agassiz observes that "to form an idea of 

 his true appearance, one must meet him as he swims along 

 at midday, rather lazily withal, his huge semi-transparent 

 disc with its flexible lobed margin glittering in the sun and 

 his tentacles floating to a distance of many yards behind 

 him. Encountering one of these huge jelly fishes when 

 out in a rowing boat, we attempted to make a rough 

 measurement of his dimgnsions upon the spot. H-vas 

 lying quietly near the surface, and did not seem in the 

 least disturbed by the proceeding, but allowed the oar, 

 eight feet in length, to be laid across the disc, which proved 

 to be seven feet in diameter. Backing the boat slowly 

 along the line of the tentacles, which were floating at their 

 utmost extension behind him, we measured these in the 

 same manner, and found them to be rather more than 

 fourteen times the length of the oar, thus covering a space 

 of some hundred and twelve feet." This huge mass is 

 produced by a hydroid measuring not more than half an 

 inch in length when full grown. 



The parasitic early life of Caiupanella pachydcrvia 

 A. Ag. appears to throw a doubt whether this acaleph passes 

 through the hydroid state or not. Should the eggs de- 

 velop at once into the medusa in this instance, there is no 

 small significance to be attached to the fact. An anomaly 

 of an opposite character is noticed in the case of Laoincda 

 amphora Ag. This campanularian develops medusas 

 which never separate from the parent hydroid, but wither 

 on its stem after having laid their eggs. The development 

 of these abortive medusx- is not far advanced. This 

 species flourishes in the sewage of Boston. There is a very 

 admirable drawing of Tubularia Coutkouyi Ag., a tubu- 

 larian whose medusa buds are never freed from the stem, 

 and do not develop into full-grown jelly fish, but always 

 remain abortive. These buds cluster like a bunch of 

 grapes under the expanded umbrella-shaped tentacles of 

 the hydroid, which are gracefully supported by a curved 

 stem. 



The process of the budding of the medusae of Hybocodon, 

 where small jelly fish similar to the original grow by gem- 

 mation from a large tentacle, is well described, and the 

 hydroid stage and general want of symmetry in the 



