diff --git a/data.py b/data.py
index 3aa74d2..f31995b 100644
--- a/data.py
+++ b/data.py
@@ -28,12 +28,49 @@ FILENAME = './game.sqlite'
 conn = None
 
 
+TABLES = [
+    '''\
+    create table populations (
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        species TEXT,
+        pop INTEGER,
+        planet INTEGER,
+        FOREIGN KEY(planet) REFERENCES planets(id)
+    )''',
+    '''\
+    create table stars (
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        x INTEGER,
+        y INTEGER,
+        radius INTEGER,
+        name TEXT UNIQUE
+    )''',
+    ('''\
+    create table planets (
+        id INTEGER PRIMARY KEY,
+        ordo INTEGER,'''  # The order from the star, counting from 1.
+        # I use "ordo" instead of "order" because "order" is a keyword
+        # in SQL (or at least it caused a syntax error in SQLite.)
+
+        # These capacities are fixed and reflect the conditions on the
+        # planet in a very abstract way.  Bio and Industry should be
+        # low/high near and far from the star and high/low in the mid-
+        # range, but for now I'm just going to use random numbers.
+     '''bio_capacity INTEGER,
+        bio INTEGER DEFAULT 0,
+        industrial_capacity INTEGER,
+        industry INTEGER DEFAULT 0,
+     '''
+     '''star INTEGER,
+        FOREIGN KEY(star) REFERENCES stars(id)
+    )'''),
+    ]
+
+
 def initialize_db_tables(filename):
     conn = open_db(filename)
     c = conn.cursor()
-    for statement in stars.TABLES:
-        c.execute(statement)
-    for statement in population.TABLES:
+    for statement in TABLES:
         c.execute(statement)
     c.close()
     conn.commit()
diff --git a/game.sqlite b/game.sqlite
index 54b5b4b..85b246d 100644
Binary files a/game.sqlite and b/game.sqlite differ
diff --git a/population.py b/population.py
index 40b003e..fc13b95 100644
--- a/population.py
+++ b/population.py
@@ -20,18 +20,6 @@
 from random import sample
 
 
-TABLES = [
-    '''\
-    create table populations (
-        id INTEGER PRIMARY KEY AUTOINCREMENT,
-        species TEXT,
-        pop INTEGER,
-        planet INTEGER,
-        FOREIGN KEY(planet) REFERENCES planets(id)
-    )''',
-    ]
-
-
 INITIAL_POP = 1000
 INITIAL_NUMBER_OF_SENTIENT_PEOPLES = 12
 
diff --git a/server.py b/server.py
index 8780cad..8af7265 100644
--- a/server.py
+++ b/server.py
@@ -69,16 +69,20 @@ def population_grows(db_cursor):
         from populations join planets
         on populations.planet = planets.id
         ''')
+        # and populations.home_star = planets.star
+        # People are only legally allowed to reproduce in their home
+        # stellar systems.
     pops = list(db_cursor.fetchall())
     for pop_id, pop, planet_id, bio in pops:
         if pop > bio:
             # famine and death!  Woe!
+            print('WARNING population crash on planet {planet_id}!')
             pop = bio >> 1
             bio //= 10
         else:
-            bio -= pop  # Everyone eats.
-            new_pop = round(pop * POP_GROWTH)
-            pop += new_pop
+            # Everyone eats.
+            bio -= pop
+            pop += round(pop * POP_GROWTH)
         print(f'population {pop_id} of planet {planet_id} is now {pop}, bio is {bio}')
         db_cursor.execute('update planets set bio = ? where id = ?', (bio, planet_id))
         db_cursor.execute('update populations set pop = ? where id = ?', (pop, pop_id))
diff --git a/stars.py b/stars.py
index 1270a41..a49b56f 100644
--- a/stars.py
+++ b/stars.py
@@ -67,36 +67,6 @@ WIDTH, HEIGHT = 10240, 7680
 
 # Database stuff.  SQL, etc.
 
-TABLES = [
-    '''\
-    create table stars (
-        id INTEGER PRIMARY KEY AUTOINCREMENT,
-        x INTEGER,
-        y INTEGER,
-        radius INTEGER,
-        name TEXT UNIQUE
-    )''',
-    ('''\
-    create table planets (
-        id INTEGER PRIMARY KEY,
-        ordo INTEGER,'''  # The order from the star, counting from 1.
-        # I use "ordo" instead of "order" because "order" is a keyword
-        # in SQL (or at least it caused a syntax error in SQLite.)
-
-        # These capacities are fixed and reflect the conditions on the
-        # planet in a very abstract way.  Bio and Industry should be
-        # low/high near and far from the star and high/low in the mid-
-        # range, but for now I'm just going to use random numbers.
-     '''bio_capacity INTEGER,
-        bio INTEGER DEFAULT 0,
-        industrial_capacity INTEGER,
-        industry INTEGER DEFAULT 0,
-     '''
-     '''star INTEGER,
-        FOREIGN KEY(star) REFERENCES stars(id)
-    )'''),
-    ]
-
 
 def init_db(conn):
     print('Generating star data.')