Meteorological Observations. 431 



Note on the Reproduction of Leeches, By M. Fremond. 



In this memoir M. Fremond informs us what are the most favour- 

 able conditions for the preservation of leeches, but we must refer our 

 readers to his paper for all particulars concerning the construction of 

 reservoirs and the plants most proper to be put into them, merely 

 giving here some of the details furnished by him on the development 

 of these animals. 



The reproduction of leeches is effected, according to circumstances, 

 either by cocoons or compound eggs, which are usually hatched at the 

 end of forty days. The egg is formed of a transparent membrane, 

 full of a liquid, in which little globules soon begin to appear ; these 

 globules are in fact so many gertns of leeches, and during develop- 

 ment take the form of little worms, which soon leave the egg by an 

 opercular hole at its extremity. The young leech is white when just 

 hatched ; it does not begin to acquire colour until some hours after- 

 wards, and only arrives at its perfect colouring when two years old ; 

 its first food consists of the mucous matters which cover the leaves of 

 aquatic plants ; afterwards, when its mouth has attained a more com- 

 plete development, it feeds on the larvae of insects and other small 

 animals. — Comptes Rendus, 12 Mai, 1851. 



METEOROLOGICAL OBSERVATIONS FOR SEPT. 1851. 



Chiswick. — September 1. Cloudy and fine : overcast. 2. Drizzly : cloudy and 

 fine. 3. Hazy : very fine : clear. 4. Foggy : cloudy : fine. 5. Very fine : 

 clear. 6. Fine : cloudy. 7. Clear : very fine. 8. Overcast : cloudy and fine. 

 9 — 13. Mornings foggy : days very fine : nights clear. 14. Slight fog : very 

 fine. 15. Slight fog : cloudy and fine. 16. Light clouds and fine : over- 

 cast. 17. Overcast: fine: cloudy. 18,19. Fine: clear. 20 — 22. Very fine* 

 23. Slight fog: very fine : rain. 24. Foggy: overcast: foggy at night. 25. 

 Slightly overcast : rain. 26. Partially overcast : cloudy : clear. 27. Cloudy : 

 drizzly. 28. Clear and fine. 29. Foggy : fine. 30. Rain : overcast. 



Mean temperature of the month 55 0, 15 



Mean temperature of Sept. 1850 54 -23 



Mean temperature of Sept. for the last twenty-five years . 57 '18 

 Average amount of rain in Sept 2'61 inches. 



Boston. — Sept. 1. Fine. 2. Cloudy: rain early a.m. and p.m. 3 — 5. Cloudy. 

 6. Fine. 7. Cloudy. 8— 11. Fine. 12, 13. Foggy. 14. Fine. 15— 17. Cloudy. 

 18, 19. Fine. 20. Cloudy. 21—23. Fine. 24. Cloudy. 25. Cloudy: rain p.m. 



26. Cloudy : rain a.m. and p.m. 27. Cloudy. 28, 29. Fine. 30. Cloudy. 



Sandwich Manse, Orkney. — Sept. 1 . Drizzle : damp. 2. Cloudy : rain. 3. 

 Drizzle : cloudy. 4. Clear : aurora. 5. Clear. 6. Bright : cloudy. 7. Cloudy : 

 clear : aurora. 8. Clear. 9. Bright : hazy. 10. Cloudy : drops. 11. Cloudy: 

 fine. 12, 13. Bright : fine : clear. 14. Bright: cloudy. 15. Cloudy : clear : 

 aurora. 16. Bright : clear : aurora. 17. Bright : clear. 18,19. Fog: cloudy. 

 20. Showers: clear. 21. Cloudy. 22. Drops: drizzle. 23. Bright: clear: 

 aurora. 24. Clear : cloudy. 25. Showers : sleet showers. 26. Bright : showers. 



27. Clear : showers : aurora. 28. Bright : showers : aurora. 29. Cloudy. 30. 

 Cloudy : showers. 



