1897-98.] On the Diatomacece. 359 



requisites. It will also save time and disappointment if, in 

 your outfit, which may be very modest, you have something 

 which will enable you to test a gathering upon the spot. 

 This can be done by a pocket-lens ; but the most convenient 

 form of lens for this purpose is that known as an Algen- 

 sucher, which can be purchased at any optician's — at least at 

 any optician's who is agent for a German house — for a few 

 shillings. To carry your gatherings home, you require a 

 number of wide-mouthed bottles of two or three ounces capa- 

 city, and with good corks. For the purpose of wrapping up 

 gatherings of wet alga?, pieces of waterproof sheeting are 

 necessary ; while for the purpose of scraping up the diatoms 

 from the face of rocks or sides of caves, or from the surface 

 of stones or mud, an iron spoon, or a piece of tin-plate bent 

 to suit, is required. For cutting diatom-bearing algse growing 

 in pools in the rocks on the sea-shore, a dessert knife is as 

 handy as anything. For those who desire to collect in deep 

 water, something more pretentious is necessary. If the water 

 is not too deep, and the collecting can be done from the land, 

 a stick which can be lengthened after the manner of a fishing- 

 rod can be used. To the end is fastened an iron spoon with 

 a broad sharp edge to its mouth, which must be bent inwards, 

 so as to scrape along the surface of the bottom of the pool. 

 If the searchings are in such places that a boat is necessary, 

 then a drag-net of some kind is required. 



When a gathering is made, and, after being tested by the 

 Algen-sucher, is found to be worth taking home, it is placed in 

 one of the wide-mouthed bottles, and a little water from the 

 same place added to keep it moist. The bottle is corked, 

 and labelled with the place where and the date when the 

 gathering was made. If it is algse or grasses to which 

 diatoms are adhering which have been gathered, they are 

 best taken home wrapped in a piece of the waterproof sheet- 

 ing, which must be also duly labelled. On arriving at home, 

 no time should be lost in taking the corks out of the bottles 

 and in spreading out the grasses or algae to dry, unless it is 

 intended to try to cultivate the diatoms, in which case they 

 must be transferred immediately to suitable water. If many 

 gatherings have been made on the same day, some kind of bag 

 or haversack may be necessary in which to carry them home. 



