92 CORRESPONDENCE. 



Natural History Notes. — Viola odorata, March 7th; Ranunculus 

 Ficaria, March 13th; Salix caprea, (female,) March 13th; Tussilago 

 Farfara, March 20th. I found a Thrush's nest, with three eggs in it, 

 to-day, March 20th. The hedges (thorn) are beginning to show a bit of 

 green, but the cold nights are keeping them back as yet. — H. F. Johnson, 

 Nottingham. 



Early Flowers. — February 25th I found Hazel, both male and 

 female flowers, and on the 26th the Barren Strawberry (Potent ilia 

 Fragariastrum,) and the perennial Dog's Mercury; March 3rd, a 

 Dandelion ; March 8th, Lesser Celandine (Ranunculus Ficaria) and 

 Coltsfoot ; March 13th, Wood Anemone ; March 15th, Willow ; March 

 21st, Moschatel, (not quite out ;) and March 24th, Wood Sorrel and 

 Green Hellebore. — O. M. F., Frankton, Salop. 



Another Boulder. — I noted, a few days since, a fine erratic block 

 lying in a field between the villages of Batby and Glenfield, and about 

 four miles west of Leicester. It rests upon a thin stratum of drift con- 

 taining quartzite pebbles, under which the red marls of the Keuper are 

 seen in a brook-course close by. The boulder measures 3| by 3 by 2 feet, 

 and consequently weighs about 1J tons. It is of Mountsorrel granite, 

 somewhat rounded, and contains several dark patches or inclusions, 

 some of which look much like the volcanic ashes of Charnwood Forest, 

 caught up by the granite when it invaded the sedimentary rocks. Such 

 " inclusions" are very common in the Mountsorrel rock ; the majority of 

 them, however, are found, when examined microscopically, to be only 

 granite of a finer grain than the mass, the crystals being smaller. The 

 boulder lies six miles S.S.W. of its original home, the hummock of 

 igneous rock which forms Mountsorrel and Buddon Wood. It is only one 

 mile due south of the syenite of Groby. Its height above sea level (by 

 Aneroid) is about 270 feet.— W. J. H. 



Botanical Notes from South Beds. — Primula vulgaris. — These 

 flowers were cut off by the frosts at the end of January, and re-appeared 

 at the end of February. Mercurialis perennis. — Many staminate plants 

 showed their spikes of unopened flowers on February 29th, but no 

 pistillate ones were observed. Coryhis Avellana. — Blossoming freely on 

 February 22nd. Tussilago Farfara. — Many plants in blossom on railway 

 banks, with southern aspect, on March 3rd. Lamium purpureum. — First 

 blossom noticed on March 10th, on a bank with a south-west aspect. 

 Viola odorata. — Earliest observed blossoms in the open country on March 

 10th. Salix caprea. — In full blossom by March 13th. Adoxa moscliatellina. 

 — Foliage and inflorescence about three inches high, but flowers unopened 

 March 13th. Anemone nemorosa. — In blossom in a sheltered wood March 

 13th. Helleborus viridis. — First foliage showed above ground on February 

 11th. Ranunculus Ficaria, Caltha palustris, and Petasites vulgaris, in full 

 blossom March 13th, in a boggy meadow, under trees. — J. Saunders, 

 Luton. 



A Method of Testing the Definition of Oeject Glasses. — When 

 the Rev. W. H. Dallinger visited Birmingham to lecture on his 

 important researches into the minutest forms of life, he favoured me 

 with some information on his methods of manipulating the very high 

 powers he used in these researches. In the course of conversation, in 

 reply to my enquiry whether or not he considered that the indications of 

 a power so high as the l-72nd could be relied on, he stated he could 

 place as much reliance on it as on one of lin. focus ; and explained, he never 

 used any power which he had not tested on an object, which he could 

 verify with the naked eye. To do this, he takes any clearly defined 

 object, such as a watch dial, and placeB it in the position which the 



