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The article focuses on Glyceria aquatica, a perennial grass native in the British Isles. It discusses the distinguishing characteristics of the grass as well as its habitat. It indicates that Glyceria contains a high proportion of hydrocyanic acid which is present in the organs of the plant. It rapidly grows on the drainage dykes and river banks. Moreover, the grass has been considered for economic use as a valuable crop in Great Britain and as a pasturage for cattle. However, harvesting of Glyceria has been limited due to high labor costs.

The supposedly obligate epiphyte Smithora naiadum, normally found only on the sea grasses Phyllospadix scouleri and Zostera marina, grew on an artificial substrate under field conditions. This development shows that the alga does not appear to require a chemical factor from its normal host plant for (1) substrate selection and adhesion, (2) growth of basal cushion and young blades, or (3) maturation of thick cushions. [ABSTRACT FROM AUTHOR]

The article presents a research report on the overgrazing of seagrasses by a regular urchin, Lytechinus variegatus which occurred in a large area off Dixie County, Florida, in the Gulf of Mexico. It mentions that the grassbed overgrazed by L. variegatus extends southward from Steinhatchee River to Horseshore Point, a distance along the coast about 26 km, and extends offshore as far as 5.5 to 9.25 km in depths of 0.3-3 m (mean low water). The report notes that the prime concern resulting from overgrazing by L. variegatus is possible permanent denudation of grassflats. It also highlights several factors responsible for the L. variegatus explosion.

A correction to the articles "Tenure#x2013;Why Keep It?," published in the April 1973 issue, and "Overgrazing of Seagrasses by a Regular Urchin, Lytechinus variegatus" published on the April 1973 issue is presented.

The article offers a description of an effective alternative method for obtaining gametes from the sea urchin, Strongylocentrotus purpuratus. It mentions that alternative method involves no chemicals which might influence the behavior of the gametes, and the animal survives during procedure without apparent damage and can be reused as a source of gametes. The procedure involves approximately 5 to 10 milligram of air is injected into the coelomic cavity using a 5 ml syringe, then the syringe needle is inserted through the peristomial membrane of the animal and the air is injected rapidly; the procedure is repeated if necessary. It concludes that because this procedure often produces a back spray of coelomic fluid, it is advisable to use the other hand to cover the peristomial area.